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Spallanzani, Lazzaro


(b. Scandiano, Italy, 12 January 1729; d. Pavia, Italy, 11 February 799)

natural history, experimental biology, physiology.

Among the many dedicated natural philosophers of the eighteenth century, Spallanzani stands preeminent for applying bold and imaginative experimental methods to an extraordinary range of hypotheses and phenomena. His main scientific interests were biological and he acquired a mastery of microscopy; but he probed also into problems of physics, chemistry, geology, and meteorology, and pioneered in volcanology. Acute powers of observation and a broadly trained and logical mind helped him to clarify mysteries as diverse as stone skipping on water; the resuscitation of Rotifera and the regeneration of decapitated snail heads; the migrations of swallows and eels and the flight of bats, the electric discharge of the torpedo fish; and the genesis of thunderclouds or a water-spout. His ingenious and painstaking researches illuminated the physiology of blood circulation and of digestion in man animals, and also of reproduction and respiration in animals and plants. The relentless thoroughness of his work on the animalcules of infusions discredited the doctrine of spontaneous generation and pointed the way to preservation of foodstuffs by heat.

Spallanzani’s father, Gianniccolò, was a successful lawyer. He was of locally established stock; and his wife, Lucia Zigliani, came of good family from Colorno, in the duchy of Pharma. The natal house is still preserved in Scandiano, a in the province of Emilia, northeast of the Apennines. They had a large, closely knit family, but of Lazzaro’s siblings only two sisters and a brother feature in his letters. His younger brother Niccolò. who acquired a doctorate in law and wide knowledge of agronomy, and his sister Marianna, who became a naturalist, shared many of his scientific interests; both survived him.

After attending the local school, Lazzaro went at age fifteen to a Jesuit seminary in Reggio Emilia, seven miles away, where he excelled in rhetoric philosophy,and languages. The Dominicans wanted him to join their order. Instead, he left Reggo Emilia in 1749 to study jurisprudence at the ancient University of Bologna, where Laura Bassi, cousin on the paternal side, was professor of physics and mathematics. Under this remarkable woman’s influence, Spallanzani liberalized his education New subjects included mathematics, which impressed him with the significance of quantitative exactitude, while physics, chemistry, and natural history aroused his curiosity and revealed his bent. His classical talents, stimulated and polished, brought lasting advantages in historical awarenes and aptness of self-expression; and he acquired an invaluable knowledge of Erench. For some three years he also worked toward his doctorate in law, a project that familiarized him with logic but otherwise grew distasteful. With Laura Bassi’s support Antonio Vallisneri the younger, professor of natural history at Padua and a fellow Scandianese, secured paternal consent for Lazzaro to abandon jurisprudence and follow his predilections.

In 1753 or 1754 Spallanzani became a doctor of philosophy. Then, having received instruction in metaphysics and theology, he took minor orders. Within a few years he was ordained priest and attached to two congregations in Modena. By 1760 he was designated “l’Abate Spallanzani” and was generally known as such thereafter. His priestly offices were performed irregularly; nevertheless, even in later life he still officiated at mass. Since he had no private income, the financial assistance (and moral protection) of the church facilitated his investigations of natural phenomena.

Apart from casual religious commitments, and despite an insatiable enthusiasm for travel, his career was wholly academic and centered in Lombardy. The main features of his last thirty years (1769–1799) as professor of natural history at Paivia are documented adequately, and his per of tenure in the chair of philosophy at Modena now seems settled as 1763 to 1769; but some aspects of his intial appointment at Reggio Emilia remain unclear. Loss of earlier letters and lack of other records misled biographers into discrepant conjectures. Fortunately, fresh and dependable data are available in his Bibliografia (1951) and Epistolaria (1958–1964).

Reggio Emilia . Early in 1755 Spallanzani began teaching logic, metaphysics, and Greek at the ancient College of Reggio Emilia. Two years later he was appointed lecturer in applied mathematics at the small, recently founded University of Reggio Emilia. In 1758 he was concurrently professor of both Greek and French at Nuovo Collegio, which, presumably, replaced the old seminary. The university lectureship remained unaltered in title, but in 1760 his chair at the college was designated languages and by 1762 had become Greek.

Spallanzani assisted in the public oral examinations of graduating students, and his first publication was possibly the anonymously compiled booklet of astronomical questions headed Ex coelestibus corporibus, and variously titled Theses philosophicae... and Propositiones physicomathematicae...(1757—1759), which served as the basis for interrogating candidates. During this period also, certain literary and philosophic papers read by him to the Accademia degli Ipocondriaci at Reggio Emilia may have appeared anonymously in print. His first acknowledged publication is a critique of A. Salvini’s Italian translation of the Iliad. This work, Riflessioni intorno alla traduzione dell’lliade del Saivini...1760), comprising three letters addressed to Count Algarotti, chamberlain to Frederick the Great of Prussia, displayed intimate understanding of Greek style and metaphor. In numerous examples Spallanzani showed that the translator’s prolixity enfeebled the vigor of ihe original and that the Italian language, when chosen felicitously, conserved the beauty and pith of Homer.

In the summer of 1761 Spallanzani set out for the Reggian Apennines and Lake Ventasso, on the first of many scientific excursions to various parts of Italy and elsewhere, in the multiple capacities of natural historian in the broadest sense, field investigator of unexplained occurrences, aggressive collector of museum specimens, and observer of humanity. An indefatigable walker and daring climber, his main concern on this journey was the origin of springs and fountains gushing from the mountain slopes. Descartes’s contention that the source was seawater, purged of salinity by subterranean fires after reaching the mountain sides through devious channels, was superseded after 1715 by an unconfirmed hypothesis of Antonio Vallisneri the elder, who stated that water precipitated near the summit, whether as snow, rain,or mist, insinuated itself between sloping strata of the mountain and descended by gravity until an by an impervious stratum, whereupon it emerged from some hidden reservoir. Spallanzani verified the latter concept by observing such factors as the relationship between the number and size of springs and total precipitation in the area; the water-condensing characteristics of the mountain involved; and the disposition, nature, and water affinity of the constituent strata. Further, he disproved a local belief that a great whirlpool existed in the middle of Lake Ventasso. Embarking on a raft improvised of beech stumps, he sounded the depth of the lake at various points, including its center, afterward tracing its origin to two fountains. His report (1762) appeared in the form of two letters to Vallisneri the younger.

Spallanzani was introduced by Vallisneri in 1761 to works by Buffon and to those by his occasional collaborator, the English priest and microscopist John Turberville Needham. For some twenty years thereafter Spallanzani recurrently focused his attentions upon the fundamental phenomena of vitality and reproduction and on the doctrines Buffon and Needham concerning them. Buffon claimed in the second volume (1749) of Histoire naturelle that all plants and animal matter (including seminal fluid) decomposed ultimately into minute motile particles, termed “organic molecules,” which served as elementary building blocks for the reconstitution of every form of life. Buffon contended he could identify these particles in Needham’s microscopic preparations. Needham an enthusiastic but erratic experimenter, hurriedly published further surmises in Nouvelles observations microscopiques...(1750), an expanded French version of a letter to the Royal Society of London on the generation, composition, and decomposition of animal and vegetable substances. Needham described animalcules that developed in many kinds of infusions, despite precautions to exclude external air. These animalcules, and like wise those in spermatic fluid, eventually languished, died, and disintegrated. Their debris, with that of decomposing plants, resolved into filaments yielding “animals of an inferior species.” traced various other fancied modes and sequences of renascence. The agent provoking such spontaneous generation was designated a productive “vegetative force.” present in the most minute component of organic matter.

Equipped in 1762 with an adequate microscope. Spallanzani began to repeat Needham’s experiments. The work was interrupted by his departure from Reggio Emilia. Supposedly, chairs had been offered him from as far afield as Coimbra and St. Petersburg and also from neighboring Modena and Cesena. In 1763 he went to Modena as professor of philosophy at the university and at the College of Nobles. Here he was still only fourteen miles from the family home at Scandiano.

Modena . Francesco Redi’s experiments on fly maggots in 1668 had dispelled the myth of spontaneous generation for complex animals. But the notion was reapplied to lesser forms of life after the pioneer microscopist Leeuwenhoek described the little animals teeming and cavorting in his infusions (1674); he and several of his successors supposed that these animals were of atmospheric origin. Spallanzani verified this surmise experimentally and proved the animalcules did not arise spontaleously. His infusions of vegetables or central leeds, whether boiled or unboiled, in plugged or open vessels, yielded various microorganisms, possessing such attributes of animality as definite shape, orderly motion, and ability to withstand certain degrees of heat or cold. Whereas Needham had abandoned as unavailing and superfluous all precautions designed to control these infusoria, spallanzani redoubled efforts to prevent their apparance. In hundreds of experiments he tested arious rituals for rendering infusions permanently barren and finally found that they remained free of microorganisms when put into flasks that were hermetically sealed and the contents boiled for one hour. The entrance of air into the flask through a slight crack in its neck was followed by proliferating infusoria. His masterful essay, dedicated to the itogna Academy of Sciences. Saggio di osservazioni microscopiche. . . (1765), reported no spontaneous generation in strongly heated infusions protected from aerial contamination, Further, the causes of Needham’s misinterpretations were analyzed and Buffon’s assertions about organic molecules refuted. The work first appeared jointly, under the title Dissertazioni due. . . , with a short this in Latin about the mechanism of stone skiply on water, De lap’tdihus ah aqua resiiientibus.This latter tract, dedicated to Laura Bassi, explained “ducksand drakes” physicomathernatically.

Charles Bonnet at Geneva had predicted (unknown to Spallanzani) in his Considérations surles corps organisés (1762) that Needham’s claims would prove fallacious. A uniquely constructive and durable friendship developed between Bonnet and Spallanzani following the former’s receipt of a copy of the Saggio. In 1765. after cutting up thousands of earthworms and exploiting the ability of the aquatic salamander to regrow its tail, Spallanzani resolved to investigate reproductive phenomena in animals and plants. He received encouragement from Bonnet (coupled with a warning against spreading his energy among too many problems) and began to study methodically the regeneration of lost parts in lower animals. This phenomenon, brought to attention twenty years earlier by Trembley’s work on regrowth in polyps, had been extended to earthworms by Réaumur and Bonnet himself. Spallanzani found the precise location of those cuts in earthworms that affected the segmental regenerative response. Other species of worms displayed different reactions after being divided. Amputation of the tail of the freshwater boat worm, the young aquatic salamander, and the tadpole was followed by vascularization of the transparent growing stump, observable microscopically. Regenerative capacities of remarkable complexity and repetitiveness were noted in the horns of the slug: in the foot, horns, and head of the land snail; the limbs and jaw of the salamander; and the limbs of the toad and forg. Besides adding to the knowledge of the potentialities of the mechanism, Spallanzani established the general law that in susceptible species an inverse ratio obtains between the regenerative capacity and age of the animal.

Early in 1768 he reported these findings in Prodromo di un opera da imprimersi sopra le riproduzioni animali, which he intended as a prelude to a major work on animal reproduction. Reactions ranged from surprised interest to disbelief, particularly as regards the ability of decapitated snails to produce completely new heads. Some of his peers, on attempting to repeat the work, reported deaths or only partial regenerations in such snails; others confirmed his findings, including Bonnet and Senebier at Geneva, Laura Bassi, Lavoisier, and the Danish naturalist Müller. Spalianzani promptly sent a copy of the Prodromo to the secretary of the Royal Society of London (who translated it into English), and in that same year he was elected a fellow of the society. He detailed his experiments involving more than 700 decapitated snails in Resultati di esperienze sopra la riproduzione delta testa nelle lumache terrestri (1782, 1784).

Two other publications appeared in 1768. The first, Memorie sopra i muli..., was a collection of communications about hybrids by Bonnet and various authors, edited by Spallanzani, who urged that experiments on insect hybridization were a possible means of disentangling the problem of generation. He did not pursue this particular path but later attempted to cross batrachian species and even such diverse animals as cats and dogs, A second booklet. Dell’azione del cuore ne’ vasi sanguini, outlined his findings on the action of the heart upon the blood vessels and was addressed to the great physiologist Albrecht von Haller,

Haller’s microscopic observations of blood movements in his Deux mémoires sur le mouvement du sang (1756) had been made by refracted light on medium-sized vessels in the isolated mesentery of the frog. Spallanzani, using P. Lyonet’s novel dissecting apparatus, conducted his observations mostly in a darkened room with reflected light from sunbeams impinging upon exposed parts of the aquatic salamander. He systematically noted how the cardiac systolic force motivated the blood circulation. The rhythmic inequality of blood flow in the aorta and large vessels disappeared in medium and small arteries, becoming regular and uniform, The velocity diminished in the smaller vessels, but sinuosities did not retard the flow. In the smallest vessels, individual red corpuscles negotiated acute angles and folds by elastically changing shape. The blood velocity in the venous system increased as the caliber of the vessels enlarged. Halter responded to the many amplifications and corrections of his work by securing Spallanzani’s election to the Royal Society of Sciences of Göttingen.

Pavia . His scientific accomplishments and growing renown as an eloquent, informative lecturer brought offers of chairs at Parma and Pavia. The latter city had been in Austrian hands for more than fifty years, and Maria Teresa’s government sought to restore some of its ancient dignity by appointing new professors to a reconstituted university. The prospect of higher emoluments and greater distinction proved irresistible, and Spallanzani became professor of natural history at Pavia in November 1769, He had just completed a painstaking Italian translation of Bonnet’s philosophic and eloquent Contemplation de la nature; and he looked forward to his official duties being confined to natural history — “my dominating passion for several years.” A recent French version of the Saggio, elaborately annotated by Needham, contended that excessive heat enfeebled or destroyed the vegetative force of infusions and impaired the essential elasticity of air within sealed flasks. Spallanzani had lost patience with his opponent; “Quelle confusion, quelle obscurityé règne-t-il dans ses notes à mes observations microscopiques! Quelles monstruosités dans ses pensées!” he complained to Bonnet. His inaugural address, delivered in Latin and published as Prolusio...(1770), made clear his intention to settle the dispute with Needham and to rebut the peculiar views of his supporter Buffon. Meanwhile, educated laymen aligned themselves with scientists on each side of the spontaneous generation controversy, as happened a century later over Darwinian theories.

Spallanzani found his daily lectures taxing, and other duties interrupted his researches. He took charge of the public Museum of Natural History of the university, the development of which the court at Vienna supported through its minister plenipotentiary, the governor of Lombardy, Count Carlo di Firmian. The acquisition of exhibits proves congenial to Spallanzani’s aggressive instincts and broad vision, so that within a decade the collecttions of the museum were among the most magnificent in Italy. In the summer of 1772, when the government sent him to visit the mines and collect fossils in the Alps north of Milan, his itinerary included lakes Como and Maggiore, and the towns and villages of Ticino. Less agreeable distractions ranged from the procurement and disposition of new specimens to the preparation of a complete catalogue. Nevertheless, because of his energy, versatility, and enterprise, Spallanzani secured monumental collections for posterity and also made lasting contributions to science in Pavia.

Spallanzani launched countless experiments relating to infusion animalcules and “spermatic worms.” with results that soon made a chimera of the vegetative force and undermined the doctrine of organic molecules; but unforeseen complications or fresh ideas demanded further investigation, and publication was postponed. His previous observations on the physiology of circulation were expanded to include species of frogs and lizards. Through a chance discovery in 1771 that the vascular network in the umbilical cord of an embryonated hen’s egg could be seen clearly with the Lyonet apparatus, he first established the existence of arteriovenous anastomoses in a warm-blooded animal. He also studied the effects of growth (in the chick embryo and tadpole) upon circulatory mechanisms; the influence of gravity and the consequences of wounds on different parts of the vascular system; and changes in the languid or failing circulation in dying animals. Finally, Spallanzani demonstrated that the arterial pulse is due not to mere cardiac displacements but to lateral pressure upon an expansile wall from cardiac impulsions conveyed by the blood column. A total of 337 experiments were outlined and expounded in four dissertations, forming a treatise on the dynamics of circulation that appeared as De’ fenomeni della circolazione...(1773).

Spallanzani’s next outstanding publication, Opuscoli di fisica animale e vegetabile...(1776), contained five reports that displayed unexcelled experimental skill, remarkable powers of observation, and lucid literary talent. The first volume included the long-deferred treatise on infusoria, “Osservazioni e sperienze intorno agli animalculi delle infusioni. . .” This work challenged Needham’s concept of a heat-labile vegetative force by comparing the growth-promoting qualities of various infusions preheated to different extents and left in loosely stoppered flasks. After several days infusions that had been boiled for two hours generally slowed better growth than corresponding preparations boiled for shorter periods. Profuse growth appeared in infusions made from vegetable seeds reduced to powder in a coffee roaster or burned to a cinder by a blowpipe. Spallanzani concluded that the vegetative force was imaginary. He disposed of Needham’s other objection by instantaneously seeling the capillary end of the drawn-out neck of each infusion flask. Thus rarefaction of the enclosed air was avoided, and the sterility of boiled infusions could be attributed no longer to diminshed elasticity of air in the sealed flasks.

Spallanzani also found that complex infusoria are more susceptible to heat and cold than the “infinitely minute” germs of lower class, whose relative resistance he ascribed to their eggs. He sought comparisons between such effects and the influence of temperature upon seeds and their respective plants; upon frog spawn, tadpoles, and adult frogs; and upon species of insects and their ova. Finally, he developed a technique for isolating single animalcules in water drops; he then observed their modes of reproduction, whether by transverse division, longitudinal fission, budding, or the peculiar daughter-colony system of Volvox, which he followed through thirteen generations.

The main treatise in the second volume of the Opuscoli confirmed and extended Leeuwenhoek’s observations on spermatozoa (which began in 1677) and refuted Buffon’s erroneous concepts of their nature and origin. The latter claimed that both male and female gonads contained a fluid teeming with nonspecific, incorruptible organic molecules, of which all living matter was fundamentally constituted. Tailed spermatic vermiculi, if present, developed in stale semen from mucilagenous and filamentous components and eventually disintegrated into smaller animalcules and organic molecules. Spallanzani always used fresh semen in studying spermatozoal form, size, motion, and reactions to heat, cold, and drying. He even demonstrated their unaltered appearance in the epididymis of live dogs and a ram. Initially he had considered the spermatic vermiculi analogous to infusion animalcules; but he later concluded that the former are distinctive components of the living animal body and that they neither shed their tails nor divide. Buffon’s perversity stemmed from poor microscopy, metaphysical confusion, and overconfident eloquence; but since he had a considerable following, Spallanzani (who sincerely admired some of Buffon’s accomplishments) at first hesitated to refute him. Five years earlier, however, Bonnet had urged him to overcome such diffidence: “You have cherished no theory, but are satisfied with interrogating nature, and giving the public a faithful account of her responses.” Spallanzani therefore minced no words. Describing Buffon’s theory as “completely destroyed,” he urged him to repeat experiments “with better microscopes, forgetting his beloved organic molecules, and imposing the rule on himself to receive as truth only the images transmitted by the senses, without adding the corrections of his imagination.”

The remaining three tracts were of lesser significance. The first concerned the effects of stagnant air upon animals and vegetables, which Spallanzani was led to investigate after observing the proliferation of infusoria and germination of vegetable-seeds in sealed vessels. Impaired vitality occurred among his specimens after widely varying exposure periods. Death was accelerated when the volume of the container was diminished or the temperature Increased. Since the animals did not die from lack of air, he cautiously postulated a toxic exhalation acting upon the nervous system. Another tract concerned animalcules that “enjoy the advantages of real resurrection after death” —unlike his infusoria, which were nonrevivable after death. This resurgence from the torpid state had been earlier observed in Rotifera found in a roof gutter by Leeuwenhoek (1702) and in the Anguillae of blighted wheat described by Needham (1745). In the latter species, Spallanzani induced eleven revival cycles by alternate humidification and desiccation, without significant casualties, but found its immortality limited. He discovered in roof-tile sand two novel animalcules that had this properly, a sloth (Tardigrada) and another Anguilla species. The final communication reported that the black dust on the ripened heads of a mold engendered new moldiness when implanted on moistened bread. Powdered roots, stalks, or unripened heads of the mold were ineffective. The unusually heat-resistant “seeds” would not develop on naturally mold-resistant substrates but their proven germinal power eliminated spontaneous generation as a factor to be considered in mold production.

Late in 1780 another two-volume work appeared, of similar title but altogether different content, Dissertazioni di fisica animale e vegetabile. Volume one, a treatise on digestion, comprised six dissertations arranged in 264 sections. The second volume, on the generation of certain animals and plants, partly fulfilled the intention expressed in his Prodromo. As in the Opuscoli, two letters of analytic comment and constructive suggestions from Bonnet were incorporated. The first work, completed in not more than two years, shows Spallanzani at his best as a thorough, resourceful, and courageous physiologist, dedicated to the scientific investigation and understanding of what he called “a subject of so much beauty and utility as the function of Digestion.”

In 1777 he publicly demonstrated the great force exerted by the gizzards of fowls and ducks in pulverizing hollow glass globules, thus confirming Redi’s century-old account (1675). The French physicist Réaumur had opened a different line of investigation by persuading a kite to swallow openended tubes containing foodstuffs, which when regurgitated showed partial digestion, for which gastric fluid was apparently responsible (1752). Spallanzani greatly extended Réaumur’s experiments. He administered food samples, generally in perforated metallic tubes or spherules, to an astonishing variety of animals. The containers were recovered by regurgitation, by passage in the feces, or by sacrificing the animal, and the contents examined for weight loss and other changes. Sometimes pieces of meat were fed, to which string was attached, permitting withdrawal at will. The test animals included many bird species, from turkeys and pigeons to herons, owls, and an eagle, grouped according to stomach wall structure and feeding habits. A miscellaneous category was formed of frogs and newts, water snakes and vipers, fish, and ruminants (sheep, ox, and horse). The final group comprised cats, dogs, and one man. Spallanzani experimented on himself to the limit of endurance. The fate of foodstuffs swallowed in linen bags or wooden tubes was noted, remnants being sought in the voided containers. One piece of resistant membrane was returned twice for further digestion in his alimentary tract before it finally dissolved. Samples of gastric fluid were procured by inducing himself to vomit on an empty stomach. Crows yielded more liberal samples through sponges placed in the tubes, as described by Réaumur.

The solvent action of this fluid on foodstuffs was determined in vitro at different temperatures. Comminuted meats were most readily dissolved; but tendon, cartilage, and soft bone disappeared slowly. Bread, broken grains, and vegetable products were also susceptible. The speed of dissolution of a given food was related to the quantity of available juice, but more particularly to the prevailing temperature. Since body heat gave optimal reactions, Spallanzani sometimes kept the glass tubes containing such mixtures in his axillae. He concluded that the basic factor in digestion is the solvent property of the “gastric juice” —a term introduced by him. Trituration only makes food particles more accessible to this juice. In gizzardless animals, mastication substitutes for trituration. Nor is the digestive process associated with putrefaction; indeed, the gastric juice is strongly antiputrefactive. The acidity that mainly accounts for this property was overlooked by G. A, Scopoli, profesor of chemistry and botany at Pavia, on analyzing a specimen of gastric juice from the crow. His nugatory report was capped by Spallanzani’s own assertion that the juice “is neither acid nor alkaline, but neutral.” Nevertheless, Spallanzai suggested some “latent acid” might account milk-curdling properties. These experiment concerned only digestion in the stomach, and he realized secretions of the small intestine might “complete the process.” Despite errors and gaps, the work successfully illuminated many phenomena of gastric digestion. Biochemical techniques were not applied to such studies during Spallanzani’s life time; but he cleared the way for John Richardson Young, whose M.D, thesis for the University of Pennsylvania. “An Experimental Inquiry Into the Principles of Nutrition and the Digestive Process” (1803), emphasized the acidity of gastric juice. Only in 1824 was this reaction identified as due to hydrochloric acid.

The first dissertation in the second volume related detailed observations and original experiments (some carried out many years earlier) on natural generation in four species of frog toads and in the water newt. The prolonged amours of the mating season for the frogs and toads culminated in fertilization, shortly after the eggs were extruded from the female cloaca, through semen bedewed upon them by the tightly clasping male. Spallanzani showed that this clasp reflex persisted after severe mutilation, including amputation of limbs or even decapitation. The nuptials of the newt followed a different pattern. Without firm contact, the couple remained in close proximity until the male discharged semen into the water near the female’s cloaca, whence fertilized ova soon emerged without intromission. He adduced abundant evidence that, notwithstanding the absence of true copulation in these amphibians, actual contact between eggs and seminal fluid is essential to fecundation. When the hindquarters of the green frog were covered with waxed taffeta breeches— a device used earlier by Réaumur and Nollet—the male’s amatory clasp was undiminished, but impregnation was prevented.

The next dissertation reported Spallanzani’s recent findings on artificial fecundation. Only slight contact between mature ova and homologous seminal fluid was necessary to achieve fertilization. This fluid was sufficiently prolific to fecundate after being diluted 1:8,000 in water. Admixture with amphibian blood, bile, urine, and various tissue juices, or with human urine, was not inhibitory. But there were no cross-reactions: attempts at artificial hybridization between toads, frogs, and newts were fruitless. Bonnet, who had discovered parthenogenesis in the aphid more than three decades earlier, suggested that an electric current might serve as a nonspecific fertilizing agent. But parthenogenesis could not be induced in frog eggs either by electricity or by various body fluids; and “stimulating agents” —for example, vinegar, and lemon or lime juice—failed to replace the appropriate seminal fluid. Last-minute findings allowed Spallanzani to end this section on a positive note. By impregnateing silkworm eggs with seed from male silkworms, he succeeded where Malpighi had failed. Further, Spallanzani recorded the first artificial insemination of a viviparous animal. A spaniel bitch in heat, carefully isolated throughout the experiment, received by vaginal syringe some fresh semen from a dog of the same breed. Two months later, three healthy whelps resembling both parents were born—an event that provoked Spallanzani to aver. “I never received greater pleasure upon any occasion since I cultivated experimental philosophy.”

These two dissertations illustrated the indispensability of seminal fluid to the generative process, but Spallanzani obscured rather than elucidated how it functioned. He demonstrated that the aura seminalis could not fertilize but left the role of spermatozoa undefined, despite his previous studies of them. Indeed, he apparently welcomed the fallacious results of a single experiment that yielded tadpoles from eggs touched with droplets of semidried sperm “quite free from worms”; for this permitted him to deride the “vermieulists.” followers of Leeuwenhoek’s concept that the spermatozoon solely embodies the preformed future individual. Spallanzani thought that this mode of impregnation equally demonstrated “the falsehood of epigenesis, or of that system which has been raised from the dead, protected and caressed by Buffon... .” He himself was, in fact, a convinced preformationist, but of the “ovist” persuasion, like Malpighi. Haller, and Bonnet before him. Thus he held that the embryo was already within the ovum: a small, coiled-up tadpole awaiting only vitalization by seminal fluid in order to uncoil and grow. This belief can be traced back to 1767, when he informed Bonnet that by “rigorous comparison” (including microscopic examination) of their external and internal structure, unimpregnated and freshly impregnated eggs of frogs were identical. Since tadpoles visibly unfolded in the fertile spawn, he felt entitled to assert that “the tadpole that becomes a frog preexists fecundation.” In the following year his Prodromo contained a hint to that effect. Now, with unsubstantial evidence buttressing a fruitless concept, he publicly exemplified those very faults that he condemned in others, particularly his old adversary the archepigenesist Needham. Spallanzani’s espousal of this doctrine encouraged much futile disputation and perhaps helped to delay until the mid-nineteenth century the discovery that the spermatozoon fertilizes the ovum by actually penetrating it.

Publication of the whole work was delayed pending completion of a final section on generation in diverse plants. His observations were made principally on common vegetables and flowering plants, during summer and autumn visits to Scandiano. He thought that the striking analogies noted between animal and plant life might include their reproductive arrangements. After removing the anthers from flowering hermaphrodite plants, and safeguarding female from male blossoms in other selected species, he studied their ovaria for seed and embryo development. Again influenced by preformationist leanings, he contended that embryos appeared in all seeds prior to and irrespective of fecundation. In hermaphrodites such as sweet basil and Syrian mallow, and in the female plants of annual mercury, want of pollen rendered their seeds sterile. Here, he compared the role of pollen to the effect of seminal fluid upon dormant embryos in amphibian ova. Productive seeds were borne, without benefit of pollination, by gourds, spinach, and hemp—a claim that Spallanzani anticipated would receive disfavor from “all modern naturalists and botanists.” He admitted accumulating experimental data as foundation for a speculative disquisition on generation in plants. Unfortunately, his industrious and novel contribution did little to resolve the prevailing confusion and rancor over this complex problem.

The Dissertazioni brought Spallanzani additional recognition at home and abroad. A French version of the Opuscoli, translated with unmatched promptitude and accuracy by Senebier, the distinguished naturalist-librarian of Geneva, had expanded the circle of his readers. Followers, competitors, and opponents again increased when the same translator duly produced French editions of the dissertations on digestion and reproduction. Spallanzani’s latest publication climaxed a period of such unbounded experimentation that he may have sensed the dangers of overextension. For although during the early 1780’s he intermittently decollated snails. observed the breeding habits of his amphibia, and planned a monograph on artificial fecundation, he did not turn to new researches in experimental biology and physiology until the last five years of his life. Other possible reasons for a change of direction included the risk, largely unrecognized or ignored, of antagonizing his Pavian colleagues and even foreign specialists by overconfident pronouncements or trespassings. Tardy and unjustified evidence that he had given this kind of offense came in 1786, when the choleric John Hunter insulted Spallanzani for his work on digestion. Hunter was angered by some mild and gentlemanly criticism in “Digestione” of his vitalistic explanation of digestion of the stomach wall observed in some cases of sudden death, as reported to the Royal Society of London in 1772. A still more delayed reaction was that of a spiteful colleague, G. S. Volta, who alleged in 1795 that experiments on plant generation described in the Dissertazioni were never performed. Spallanzani replied effectively, with dignity to Hunter and bitterness to Volta.

More powerful influences were the demands made upon him for teaching, at which he excelled: he was elected rector for the scholastic year 1777–1778. Enrollment in his natural history course had increased each year and in 1780 exceeded 115. Finally, as there were large gaps in the museum collections and he was starved for travel, his curiosity and talents could be exercised on specimen-gathering excursions. His appetite was whetted in 1779, when, after several annual postponements, he enjoyed a month-long summer tour of Switzerland; during this time, he stayed for several days at Bonnet’s villa outside Geneva. There he met Senebier and other naturalists, Abraham Trembley and his nephew Jean, and H. B. de Saussure, all of whom he deeply impressed. On the return journey he called on Haller’s widow and son at Bern and visited other Swiss cities. In his letter of thanks to Bonnet, Spallanzani stated that of all the natural history museums he visited in Switzerland, only Zurich possessed one where the collections and curator were not amateurish. A few months later, with self-assurance fully harnessed to new objectives, he wrote that his sole remaining pleasure was to see the Royal Museum enlarge daily under his direction.

During the next five years, beginning in the spring of 1780, Spallanzani made several marine and overland excursions, mostly during summer vacations. He thereby corrected the deficiencies of the museum in marine biology (while he himself developed broad scientific interests in that field) on expeditions to Marseilles and the Genoese gulf in 1781, to Istrian and other northern Adriatic ports in the autumn of 1782; to Portovenere on the Gulf of Spezia in 1783; and to Chioggia, near Venice, in 1784. He also traveled to Genoa and vicinity during Easter vacations in 1780 and 1785; on the latter occasion he was equipped with meteorological instruments. In October 1783 he returned from Portovenere on foot to Scandiano, through the Carrara marble quarries and over the Apuan Alps, collecting many geological and fossil specimens on the way. He wrote happily to Bonnet of this sea and land expedition: “During the whole time I was occupied always in observing and interrogating Nature; I have assembled an astonishing collection of observations and facts, of which several appear to me very interesting and until now unknown.”

At Marseilles, Spallanzani collected 150 fish species, many of them large and rare, and in improvised quarters studied and dissected marine fauna. During the visit to Portovenere, he instituted the first marine zoological laboratory and while there described new species of fireflies and conducted studies on deep-sea phosphorescence. He refuted the claim that the torpedo fish was attracted by magnets, intrepidly showing that its greatest shock was delivered when the fish was laid on a glass plate. Excising the heart did not lessen the shock until the circulation began to fail. He showed the animal nature of corals and many other minute marine organisms and assigned several sponges and sea moss to the vegetable kingdom. He also studied marine infusoria, testaceans, and crustaceans. The Adriatic waters proved more plentiful in many species than did the Mediterranean. His intention to write a major work on the natural history of the sea did not materialize; but in open letters to Bonnet he recorded observations on “diverse produzioni marine,” from sponges, corals, and sea-mussels, to a freshwater fountain gurgling through the salt water of the Gulf of Spezia. (For further details and an amplified bibliography of his voyages and scientific excursions, G. Pighini’s account should be consulted.)

In October 1784 a prominent Venetian patron of science, Girolamo Zulian, conveyed the offer of the chair of natural history at Padua, vacant through the recent death of Vallisneri the younger. Spallanzani informed Count Giuseppe Wilzeck (successor to Firmian) that the humidity in Pavia so aggravated his gout that he must relinquish his teaching post. Although lacking the requisite length of service for a pension, he solicited special consideration because of the arduous expeditions for the museum that were made without recompense. Wilzeck offered financial concessions but overcame Spallanzani’s obduracy only by granting a leave of absence for a prolonged visit to Constantinople, in addition to a substantial salary increase. Moreover, Joseph II refused to permit his resignation and granted an ecclesiastical benefice. In August 1785 he sailed from Venice in a gunboat with a flotilla escort, as a guest of Zulian, now the Venetian envoy to the Porte. Two months later they reached Constantinople, where Spallanzani was given quarters in Zulian’s palace. Their ship had nearly foundered in a gale off Kíthira, where they refitted; then, having threaded the Cyclades, they reached Tenedos, whence the sultan’s emissaries escorted them to the locality that excavators a century later identified as the site of Homer’s Troy. Spallanzani never forgot that he was a natural historian, even while exploring territory suffused with classical and Homeric reminders. He recorded a waterspout in the Adriatic; collected medusae in the Sea of Marmara: and, during the last part of his visit, spent on the Bosporus, made elaborate geological studies, described local semiprecious stones, and studied marine fauna. Many of the social and political customs of the country, the apathy, polygamy, and excessive wealth and poverty distressed him. He secured information from a friendly seraglio physician that developed into one of his most popular lectures; collected eudiometer samples at dances to determine the effect of overcrowding on atmospheric vitiation; negotiated for crocodiles and skins of lions and tigers with the British and French ambassadors: and was received in audience and regaled with a sixtycourse repast by the sultan.

In August 1786, having dispatched the valuable museum collections by ship, Spallanzani set out with a single attendant on the unimaginably difficult return overland. Despite hazardous mountain passes, floods and torrents, brigands and cutthroats, detours were made to inspect mines and geological structures, and more specimens were collected. Reaching Bucharest through the eastern Balkans, he crossed the Transylvanian Alps to the Hungarian plain and also Buda and Pest. In December, although welcomed in high circles in Vienna and bemedaled by Joseph 11, he encountered rumors that he had enriched his personal museum at Scandiano by transferring exhibits from Pavia. In Milan he learned that certain university colleagues had circulated a defamatory letter after a subordinate, Canon Serafino Volta, curator of the Royal Museum, whom Spallanzani had recommended as a suitable temporary substitute during his absence, had visited incognito the Scandiano collection and there discovered specimens missing from the Royal Museum. Spallanzani importuned Wilzeck to establish a judicial enquiry into the calumny.

Notwithstanding the spreading scandal, Spallanzani was welcomed at the gates of Pavia by enthusiastic students, more than 400 of whom attended his first lecture. The conspirators, besides Volta, were identified as Gregorio Fontana; Antonio Scarpa, the distinguished anatomist and surgeon; and Scopoli. In common they envied his fame and resented his authoritarianism: also, each had some personal grudge against “the pasha.” Spallanzani submitted his evidence to the Royal Imperial Council, and in August an imperial decree exonerated him completely; Volta was dismissed from the university and banished from Pavia: the other parties were reprimanded and ordered to desist from troublemaking. While Volta nursed his grievances in Mantua, Fontana acknowledged his transgression and Scarpa sought to make amends; Scopoli bore the brunt of a malicious reprisal. Spallanzani considered him a plagiarist and knew that he had signed the libelous letter sent to Bonnet, Senebier, and other well-known scientists. A curious specimen, purportedly excreted by a patient, was sent to Scopoli, who designated it Physis intestinalis, a novel species of intestinal worm, and illustrated it in a text, dedicated to Sir Joseph Banks, president of the Royal Society of London. The worm was actually a cunningly teased-out portion of chicken gullet. In 1788 the hoax was revealed in a pseudonymous publication addressed to Scopoli. This work was followed by another volume, of anonymous authorship, disparaging Scopoli’s earlier text on natural history.

In 1788 Spallanzani journeyed to the Two Sicilies, mainly in order to correct deficiencies in the volcanic collections of the museum. Southern Italy had suffered for five years from intense eruptive and seismic activities. Messina was still in ruins and the countryside devastated. Vesuvius, near Naples, Stromboli and Vulcano in the Eolian Isles, and Etna on the island of Sicily, remained active. Spallanzani visited them all, undauntedly making several perilous ascents that involved great physical endurance. Vesuvius was tranquil on his first visit, but a later attempt to reach the summit was frustrated by a violent eruption. He went to within five feet of the lava pouring from the rent mountainside and accurately measured its flow rate. Just short of the crater of Etna, toxic gases rendered him unconscious; but later he peered from the rim at the boiling lava. From a cavern near the summit of Stromboli he noted that bellowing gas explosions forced up the red-hot lava and ejected massive rocks-an observation fundamental to the science of volcanology. He descended alone into the crater of Vulcano and retired with burned feet and his staff afire when sulfurous fumes prevented further identification of mineral structures. Field observations were correlated with laboratory analyses and thermal tests on volcanic specimens. A glass furnace and the Wedgwood pyrometer made it possible to determine the composition and fusion temperatures of lava and the identity of gases liberated from the melted igneous rocks.

Throughout these volcanic travels, Spallanzani’s attention focused upon innumerable phenomena. from Scylla and Charybdis to the annual passage of swordfish through the Strait of Messina; from the punctuality of migrant birds to the kindness of the stricken peasantry. Becalmed off Laguna di Orbetello, noted for its eels, he went inland to investigate by mass dissection their mysterious mode of propagation. In 1789 and 1790 he climbed the Modenese Apennines carrying chemical apparatus for examining the natural gas fires of Barigazzo and the salses. Two years later he made further studies on eels at Lake Comacchio, south of Venice. The new wonders of the Pavia museum attracted many distinguished visitors, including Joseph 11 himself in 1791. A fascinating five-volume account of these journeys, Viaggi alle due Sicilie e in alcune parti dell’ Appennino, appeared in 1792 and was dedicated to Count Wilzeck. A sixth volume was added in 1797.

Although now more than sixty years old, Spallanzani undertook several new researches. In 1794 he reported that blinded bats could fly without striking artificial obstacles. After apparently eliminating other explanations, he reluctantly postulated a sixth sense. Two Italian scientists, and also Senebier, were invited to repeat the work. All confirmed Spallanzani’s findings; but a French scientist, L. Jurine, demonstrated that blinded bats blundered helplessly into obstacles after their ears were effectively plugged. Spallanzani promptly accepted the ear hypothesis, but the notion of a chiropteran sixth sense prevailed. The extraordinary sensitivity of the ear of the bat to self-emitted supersonic notes as the basic mechanism in the directional sense of this animal was first clearly demonstrated by D. R. Griffin and R. Galambos in 1941.

Spallanzani had adopted the new chemical doctrines that developed following the discoveries, mainly by British chemists, of carbon dioxide, hydrogen, nitrogen, and oxygen during the period 1755–1774. Contrary to the claim of Johann Gottling of Jena that phosphorus would burn in nitrogen, Spallanzani denied in 1796 that this element would burn in either nitrogen, hydrogen, or carbon dioxide. When plunged into oxygen, however, phosphorus ignited with a luminosity proportional to the amount of that gas present in the eudiometer. In that year, Napoleon’s armies were overrunning Lombardy. One of Spallanzani’s biographers, the French military surgeon J. Tourdes, found his laboratory full of vessels containing different gases, the effects of which were being tested upon various substances. He was engaged already in researches that, although incomplete, formed a major contribution to the understanding of animal and plant respiration. His last personal report, appearing in 1798, contained the novel observation that whereas plants kept in water and in sunlight furnish oxygen and absorb carbon dioxide, they reverse this exchange in deep shade.

Spallanzani suffered from an enlarged prostate, complicated by a chronic bladder infection. Early in February 1799, shortly after his seventieth birthday, he became anuric and after a restless night fell unconscious. Among the medical attendants were Tourdes and Scarpa. In the ensuing week, during lucid intervals between bouts of uremic coma, he discussed experiments with colleagues, reviewed personal affairs with relatives, and recited passages from the classics. He died peacefully at night. after receiving religious offices. He was buried in the cemetery at Pavia. The heart was placed by his brother Niccolò in the church at Scandiano, while by his own wish the bladder became an exhibit in the historical museum of the university.

Three manuscript memoirs, translated and assembled by Senebier, were published posthumously in 1803 as Mémoires sur la respiration. Lavoisier’s suggestion that respiration was a form of slow combustion, with direct oxidation of carbon and hydrogen occurring in the lungs, was disputed by the French mathematician Lagrange. Spallanzani’s experimental data resolved this controversy and laid the groundwork for modern conceptions of respiratory physiology. Snails kept in an atmosphere of nitrogen or hydrogen exhaled almost as much carbon dioxide as when breathing air. Even after lung removal, snails absorbed oxygen and gave up carbon dioxide. Excised individual organs, including the stomach, liver, and heart, respired similarly. In concluding that the blood transported carbon dioxide as a product of tissue oxidation, Spallanzani discovered parenchymatous respiration-usually accredited to the biochemist Liebig half a century later. Spallanzani left additional notes on many thousands of experiments concerning the respiratory processes of animals and plants; Senebier again loyally edited these. They appeared as Rapports de l’air avec les êtres organisés... (1807). The first two volumes comprised fourteen additional memoirs on respiration, which established the basic uniformity of the respiratory process throughout the animal kingdom. The third volume concerned respiration in plants.

Spallanzani received many honors, including membership in the ten most distinguished Italian academies, and foreign associateship in a dozen famous European scientific societies. Frederick the Great personally arranged his election to the Berlin Academy of Sciences in 1776. Spallanzani made fortunate friendships with generous-minded scientists, especially Haller and Bonnet. The latter once assured him, “You have discovered more truths in five years than entire academies in half a century.” His fame was commemorated at Scandiano, Reggio Emilia, Modena, Pavia, even at Portovenere-wherever he had lived and labored-by statues, busts, tablets, museums, manuscripts, or other memorabilia.

Of middle stature, with dark eyes and complexion, domed head, aquiline nose, and pensive countenance, Spallanzani had a resonant voice and firm gait. Masterful in personality, his character was complex. He conversed eagerly and forthrightly about scientific problems but avoided political or personal topics. He did not underrate his accomplishments, often resented criticism, and was not above canvasing friends and influential acquaintances to obtain election to learned societies. Although disliking formal restraints, he flattered and cajoled authorities from whom he sought favors. His life-style was frugal, but he enjoyed good food and wine and the company of high-minded women. If his religious vows ever vexed his robust temperament, they spared him many distracting and timeconsuming obligations, and perhaps secured him from persecution by church, state, or invading armies. Considerate of relatives and friends, he could become ruthlessly angry when wronged. In unraveling the secrets of nature, every aspect of which intrigued or inspired him, he maimed and slaughtered countless animals. Among his few relaxations were fishing and hunting, and he was expert at chess. Athletic in his youth, he remained vigorous to the end.

About a decade after his death, Spallanzani was portrayed as a genius-wizard in one of E. T. A. Hoffmann’s fantastic Tales. In more recent times the overspecialized have ignored the rare scope and stature of his accomplishments and have disparaged his prodigious output as dilettantism. Allegations that nothing practical came of his splendid studies on infusorial microorganisms overlook the importance of food canning. Nicolas Appert’s... l’Art de conserver pendant plusieurs années toutes les substances animales et végétales (1810) was made possible through Spallanzani’s work on heat sterilization. To suggest that he should have gone further and discovered the germ theory of disease is to forget that 100 years later Pasteur had to repeat Spallanzani’s work before he finally laid to rest the specter of spontaneous generation; and only then could he convince a reluctant medical profession and skeptical fellow scientists that man might be brought low and killed by parasites of almost incredible minuteness. Pasteur paid his tribute daily; he commissioned a full-length portrait of Spallanzani, which hung in the dining room of his apartment.

The particular indifference of the English-speaking world to Spallanzani’s significance stems partly from linguistic difficulties. Certain translations were made into English, but some were of poor quality and none was widely circulated. There is still no version of his complete works in English. Besides, in Spallanzani’s day Britain had a number of brilliant investigators who, collectively, covered his many fields. Stephen Hales, John Hunter, Erasmus Darwin, Joseph Black, Henry Cavendish, and Joseph Priestley were among those whose combined luster outshone the multifaceted achievements of any foreign priest-polymath. Spallanzani’s countrymen view him in different perspective. In his birthplace a bust of Spallanzani stands on a marble mantel. Above it is a plaque inscribed: Natus Scandiani Clarus Ubique. Even after allowing for local pride, this assertion is surely close to truth.


I. Original Works. The only two eds. of Spallanzani’s collected writings are in Italian: Opere di Lazzaro SSpallanzani (Milan, 1825–1826) and Le opere di Lazzaro Spallanzani (Milan, 1932–1936), each 6 vols. The latter, compiled by Filippo Bottazzi and ten collaborators under the auspices of the Royal Academy of Italy, was to include Spallanzani’s letters. edited by Benedetto Biagi, but World War 11 intervened and Biagi died. Dino Prandi became coeditor, adding to the collection until 1,475 letters, written to 173 individuals or institutions (and twelve anonymous addressees), appeared as Lazzaro Spallanzani. Epistolario (Florence, 1958–1964). Prandi’s Bibliografia delle opere di Lazzaro Spallanzani (Florence. 1951) is a detailed and generally dependable bibliography. It also cites writings about Spallanzani in various languages.

Several lengthy monographs on natural history and physiology, published in Italian during the thirty-year period 1773–1803, reached wider circles through trans. into French. English, or German. The first of these, Dé fenomeni della circolazione. . . (Modena. 1773), was translated by J. Tourdes as Expériences sur la circulation. . . (Paris. 1800), and by R. Hall as Experiments Upon the Circulation of the Blood. . . (London. 1801). The next great treatise. Opuscoli di fisica, animale e vegetabile. . . . , 2 vols. (Modena, 1776). finalizes his famous work on the animalcules of infusions, “Osservazioni e sperienze intorno agli animalculi delle infusioni. . . ,” and records observations and experiments on human and animal spermatozoa, “Osservazioni e sperienze intorno ai vermicelli spermatici …” Also included are two letters to the author from Bonnet about the animalcules and reports on the effects of stagnant air on animal and plant life, the killing and resuscitation of Rotifera. and the origin of moldiness. This work was translated into French by Jean Senebier as Opuscules de physique, animale, et végétale, 2 vols. (Geneva. 1777), and into English by T. Beddoes as Tracts on Animals and Vegetables, 2 vols. (London, 1784, 1786). Another trans., by J. G. Dalyell, appeared as Tracts on the Nature of Animals and Vegetables, 2 vols. (Edinburgh, 1799), the second edition of which, entitled Tracts on the Natural History of Animals and Vegetables, 2 vols. (Edinburgh. 1803). was augmented by Dalyell’s introductory observations and by “Tracts on Animal Reproduction,” which included accounts by Spallanzani and by Bonnet of experimental reproduction of the head of the garden snail.

Another important treatise, Dissertazioni di fisica animale e vegetabile..., 2 vols. (Modena. 1780), of which a second ed. was entitled Fisica animale e vegetabile, 3 vols. (Venice, 1782), contains his experimental enquiries into digestion in various animal species (“Digestione”), reproduction in animals and plants (“Della generazione di alcuni animali... di diverse piante”), and artificial fecundation (“Sopra la fecondazione artificiale in alcuni animali”). An English version of the Dissertazioni, translated and prefaced by T. Beddoes, is Dissertations Relative to the Natural History of Animals and Vegetables, 2 vols. (London, 1784, 1789). The sections on digestion and on reproduction, translated by Senebier, appeared separately as Expériences sur la digestion de l’homme et de différentes espèces de animaux... (Geneva, 1783, 1784; facs. ed., Paris, 1956) and as Expériences pour servir à I’histoire de la génération des animaux et des plantes. . . (Geneva, 1785). These two dissertations in French, added to the Opuscules. were republished as Oeuvres de, M. I’Abbé Spallanzani. 3 vols. (Pavia-Paris, 1787).

The long account of his travels, Viaggi alle due Sicilie e in alcune parti dell’ Appennino. . . (Pavia, 1792–1797), became available in French, German, and English under the respective titles Voyages dans les deux Siciles, et dans quelques parties des Apennins, 6 vols. (Bern, 1795–1797); Des Abtes Spallanzani Reisen in beyde Sicilien und in Gegenden der Appenninen, 5 vols. (Leipzig, 1795–1798); and Travels in the Two Sicilies, and Some Parts of the Apennines, 4 vols. (London, 1798).

Spallanzani translated and annotated Bonnet’s Contemplation de la nature, 2 vols. (Amsterdam. 1764–1765). under the title Contemplazione della natura del Signor Carlo Bonnet, 2 vols. (Modena. 1769–1770). Several eds. of this work appeared. Published posthumously and translated by Senebier, were Mémoires sur la respiration (Geneva, 1803) and Rapports de l’air avecles êtres organisés... , 3 vols. (Geneva. 1807). The former appeared in Italian as Memorie sit lei respirazione. 2 vols. (Milan, 1803), and in English as Memoirs on Respiration (London, 1804).

Spallanzani’s earliest publication, variously titled Theses philosophicae... (Parma. 1757) and Propositiones physico-mathematicae... (Reggio Emilia. 1759). probably served as basis for public disputations by university degree candidates. A better-known early work is the essay of classical criticism. Riflessioni intorno alla traduzione dell’lliade del Salvini... (Parma, 1760). A short monograph, Prodromo di un opera da imprimersi sopra le riproduzioni animali (Modena, 1768), translated by M. Maty as An Essay, on Animal Reproduction (London. 1769). which included an account of regeneration of the decapitated head of the snail, was the first work of Spallanzani to appear in English.

Many reports in the foregoing vols. were published initially as tracts or booklets; others first appeared as articles in scholarly periodicals, often in the form of letters to well-known personages. Among Spallanzani’s characteristic shorter communications are “Lettere due...” [to Antonio Vallisneri], in Nuova raccolta di opuscoli scientifici e filologici..., 9 (1762), 271 -298, on the circulation of subterranean waters and the sources of fountains observed during his travels in the Reggian Apennines: and Dissertazioni due... ( Modena, 1765), comprising “Saggio di osservazioni microscopiche concernenti il sistema della generazione dei Signori di Needham e Buffon.” and “De lapidibus ab aqua resilientibus” (stone skipping on water). The former appeared in a French trans. by Abbé Regley, with added critical commentary by J. Needham, as Nouvelles recherches sur les découvertes microscopiques, et la génération des corps organisés (London-Paris, 1769). In Prolusio (Modena, 1770), his University of Pavia inaugural address, given in Latin, Spallanzani again disputed Needham’s support of spontaneous génération; and six years later the doctrine received further rebuttals in the Opuscoli, I, pp. 3–221.

Meanwhile, Spallanzani reviewed sterility in hybrids, Memorie sopre i muli... ( Modena, 1768), and reported studies on the circulation of the blood, Dell’azione del cuore... (Modena, 1768). These two short monographs, along with Dissertazioni due (1765) and Prodromo (1768), were republished in a German trans. as Herrn Abt Spallanzanis physikalische und mathematische Abhandlungen (Leipzig, 1769). A pioneering interest in artificial fecundation, revealed by the article “Fecondazione artificiale,” in Prodromo della nuova encyclopedia ltaliana (Siena, 1779), 129 -134, culminated in an account of the artificial insemination of a bitch, “Fecondaziona artificiale di una cagna,” in Opuscoli scelti sulle scienze e sulle arti... , 4 (1781), 279–282. Continued investigations of regénération phenomena, especially of the decapitated head of the snail, are summarized in “Resultati di esperienze sopra la riproduzione della testa nelle lumache terrestri,” in Memorie di matematica e fisica della società Italiana, 1 (1782), 581 -612, and 2 (1784), 506–602.

Spallanzani’s range of interests continued undiminished in later life, as witness “Osservazioni sopra alcune trombe di mare formatesi sull’ Adriatico,” ibid., 4 (1788), 473–479, which describes waterspouts in the Adriatic: “Memoria sopra le meduse fosforiche,” ibid., 7 (1794), 271 -290, on a phosphorescent jellyfish: Lettere sopra ilsospetto di un nuovo senso nei pipistrelli... (Turin, 1794), and “Lettere sul volo dei pipistrelli acciecati,” in Giornale de letterati, 13 (1794), 120–186, which record correspondence about his experiments on the sense of direction in bats; Chimico esame degli esperimenti del Sig. Gottling, professor a Jena, sopra la luce del fosforo di Kunkel... (Modena, 1796), which criticizes Göttling’s chemical explanation of the luminosity of phosphorus; and “Lettera... sopra le piante chiuse ne’ vasi dentro l’acqua e (’aria, ed esposte all’immediato lume solare, e all’ombra,” in Opuscoli scelti sulle scienze e sulle arti... , 20 (1798), 134–146, on exposure to sunlight or shade of plants kept in water or air.

Spallanzani’s reply to John Hunter is “Lettera apologetica in risposta alle osservazioni sulla digestione del Sig. Giovanni Hunter... ,” ibid., 11 (1788), 45–95. Many of his writings contained polemic passages; and vengefulness marked the anonymous letters to G. A. Scopoli, one of four colleagues who had accused him of stealing museum specimens: “Lettere due... al Sig. Dottore Gio. Antonio Scopoli... ,” and “Lettere tre... al chiarissimo Signore Gio. Antonio Scopoli, professore di chimica e di botanica...” (Modena, 1788-ostensibly “In Zoopolis”).

Details of Spallanzani’s journey to the Near East, selected from his letters and diaries, were edited by N. Campanini, Viaggio in Oriente (Turin, 1888). At Reggio Emilia, the municipal library has custody of about 200 Spallanzani MSS , many still unpublished, and also correspondence with contemporary scientists. The Natural History Museum contains a unique collection of animal, plant, fossil, and mineral specimens catalogued by A. Jona, La collezione monumentale di Lazzaro Spallanzani... ( Reggio Emilia, 1888), and historically documented by N. Campanini, Storia documentale del Museo di Lazzaro Spallanzani a Reggio Emilia (Bologna, 1888). His other great zoological collection, now at the Institute of Zoology, University of Pavia, is described by C. Jucci in L’Istituto di Zoologia “Lazzaro Spallanzani...” (Pavia, 1939). The Historical Museum of that university exhibits relics of Spallanzani, besides a small MS collection. Additional MSS and memorabilia are in the state archives at Milan.

II. Secondary Literature. Short biographical accounts in English, often unevenly selective and containing minor inaccuracies, include A. E. Adams, “Lazzaro Spallanzani (1729–1799),” in Scientific Monthly, 29 (1929), 529–537; T. Beddoes, “Translator’s Preface,” in Dissertations Relative to the Natural History of Animals and Vegetables (London, 1784), vii-xl; W. Bulloch, “L’Abbate Spallanzani. 1729–1799,” in Parasitology, 14 (1922), 409–411; G. E. Burget, “Lazzaro Spallanzani (1729–1799),” in Annals of Medical History, 6 (1924), 177–184; B. Cummings, “Spallanzani,” in Science Progress in the Twentieth Century, 11 (1916), 236–245; G. Franchini, “Lazzaro Spallanzani (1729–1799),” in Annals of Medical History, n. s. 2 (1920), 56–62; J. B. Hamilton, “The Shadowed Side of Spallanzani,” in Yale Journal of Biology and Medicine, 7 (1934–1935), 151–170; P. de Kruif, “Spallanzani,” in Microbe Hunters (New York, 1926), 25–56: A. Massaglia, “Lazzaro Spallanzani,” in Medical Life, 32 (1925), 149–169: J. G. M’Kendrick, “Spallanzani: A Physiologist of the Last Century,” in British Medical Journal (1891), 2, 888–892; F. Prescott, “Spallanzani on Spontaneous génération and Digestion,” in Proceedings of the Royal Society of Medicine, 23 (1930), 495–510; J. G. Rushton, “Lazzaro Spallanzani (1729–1799),” in Proceedings of Staff Meetings of the Mayo Clinic, 13 (1938), 411–415: and W. Stirling, Some Apostles of Physiology (London, 1902). 60–64.

Important biographic writings in French range from J. L. Alibert. “Eloge historique de Lazare Spallanzani.” in Mémoires de la société médicale d’émulation, 3 (1800). i -ccii. t o J. Rostand. Les origines de la biologie expérimentale et l’Abbé Spallanzani (Paris, 1957). Jean Senebier prefaced his trans. of three major works with lengthy essays. “Des considérations sur sa méthode de faire des Expériences et les conséquences pratiques qu’ on peut tirer en médecine de ses découvertes.” in Expériences sur la digestion de l’homme et de differentes espèces d’animaux par I’Abbe Spallanzani (Geneva, 1783), i-cxlix: “Réflexions générales sur les volcans pour servir d’introduction aux voyages volcaniques de M. I’Abbe Spallanzani,” in Voyages dans les deux Siciles et dans quelques parties des Apennins. I (Bern, 1795), 1–74: and “Notice historique sur la vie et les écrits de Lazare Spallanzani,” in Mémoirs sur la respiration par Lazare Spallanzani (Geneva, 1803), I -58. Another translator. J. Tourdes, wrote “Notices sur la vie littéraire de Spallanzani,” as a preface to Expériences sur la circulation... (Paris, 1800), 5 - 112.

Among many biographic contributions in Italian are B. G. De’Brignoli. “Dell’Abate Lazzaro Spallanzani scandianese,” in Notizie biographiche... , IV (Reggio Emilia. 1833–1841). 247–387: P. Capparoni, Spallanzani (Turin, 1941. 1948): A. Fabroni, “Elogio di Lazzaro Spallanzani,” in Memorie di matematica e fisica della società ltaliana delle scienze, 9 (1802), xxi-xlviii, which reappeared as “Vita di Lazzaro Spallanzani,” in the Opere, I (Milan, 1825–1826). vii-xxvi: P. Pavesi, “L’Abate Spallanzani a Pavia,” in Società Italiana di scienze naturali di Milano. Memorie.6 ( I90I ), fast. III: P. Pozzetti. Elogio di Lazzaro Spallanzani (Parma, 1800): and L. Salimbeni, L’Abbate Lazzaro Spallanzani ... ( Modena, 1879). A short eulogy pronounced two days after Spallanzani’s death by the leader of the 1786 “conspiracy,” Gregorio Fontana, “Mozione... in proposito della morte di Lazzaro Spallanzani.” is reproduced in Memorie e documenti per la storia del’università di Pavia.... I (Pavia. 1878). 421–422. An account of the final illness and autopsy is given by V. L. Brera. in Storia della malattia e della morte del Prof. Spallanzani (Pavia, 1801).

Scopoli’s libelous letter of 2 February 1787. conveying the accusations about Spallanzani’s museum curatorship, appears in P. Leonardi. Centenario del Prof. Giovanni Antonio Scopoli... ( Venice. 1888). Lazzaro’s nephew, G. B. Spallanzani. vigorously defended his late uncle’s reputation in L’ombra di Spallanzani vendicata... (Reggio Emilia, ca. 1802), but was rebutted in Lettera di Giovanni Martinenghi... (Pavia. 1803). Nearly a century later the alleged calumny was reviewed by P. Pavesi. “II crimine scientifico Spallanzani giudicato.” in Rendiconti del Reale Istituto Lombardo di. scienze e lettere. 2nd ser., 32 (1899), 564–568. A fuller modern account appears in Capparoni’s Spallanzani, ch. 4, 113–127.

Special appraisals are by E. Franco, “Lazzaro Spallanzani precursore dell’ industria delle conserve,” in Atti della reale stazione sperimentale per l’industria delle conserve alimentari (Parma, 1943): C. Massa, in Modena a Lazzaro Spallanzani (Modena, 1888), celebrating the dedication of the monument at Scandiano, 21 October 1888: A. Stefani, “In omaggio a Lazzaro Spallanzani nel centenario della sua morte,” in Atti e memorie della reale accademia di scienze, lettere ed arti in Padova, n. s. 15 (1899), 209–220: and T. Taramelli, “Ricordo dello Spallanzani come vulcanologo.” in Rendiconti del Reale Istituto Lombardo di scienze e lettere, 46 (1913), 937–951. Commemorative papers by Italian and foreign scientists honoring the centenary of his death are collected in Nel primo centenario dalla morte di Lazzaro Spallanzani.... 2 vols. (Reggio Emilia, 1899). A booklet, Nelle feste centenarie di Lazzaro Spallanzani 1799–1899 (Reggio Emilia, 1899). contains portraits and Italian tributes. The second centenary of his birth also was celebrated by addresses published in Onoranze a Lazzaro Spallanzani nel II centenario dalla nascità (Reggio Emilia, 1929), the most notable being a detailed review of his travels by G. Pighini, “Lazzaro Spallanzani viaggiatore,” pp. 1–441. In 1939 the University of Pavia was host to a meeting of the Italian Society of Experimental Biology and other organizations honoring Spallanzani. The memorabilia exhibited are listed by A. Lo Vasco. Catalogo della mostra in onore di Lazzaro Spallanzani, 11 Aprile-18 Maggio 1939 (Pavia, 1939). The scientific communications appear in Commemorazioni Spallanzaniane. 11–14 Aprile 1939, 4 vols. (Pavia-Milan, 1939–1940).

Writings that relate Spallanzani to the scientific setting of his century include L. Belloni, “Antonio Vallisneri ed il contagio vivo,” in II metodo sperimentale in biologia da Vallisneri ad oggi (Padua, 1962): N. Campanini, “Lazzaro Spallanzani, Voltaire e Federico iI grande,” in Rassegna Emiliana di storia, letteratura ed arte, 1 , fasc. VII (1888), 389–406, reprinted in Nelle feste centenarie... (Reggio Emilia. 1899): A. Castiglioni,’’Eighteenth Century Physiology. Haller. Spallanzani, English School,” in A History of Medicine (New York, 1946), E. B. Krumbhaar, trans. and ed., 609–614: A. Clark-Kennedy, Stephen Hales, D. D., F.R. S. An Eighteenth Century Biography (Cambridge, 1929): C. Dobell, Antony van Leeuwenhoek and His “Little Animals”... (New York. 1932: 2nd ed., 1958: paperback ed., 1960): M. Foster, Lectures on the History of Physiology During the Sixteenth, Seventeenth and Eighteenth Centuries (Cambridge, 1924), 200–254: A. von Haller, Elementa physiologiae corporis humani, 8 vols. (Lausanne-Bern, 1757–1764): A. von Muralt, “Lazzaro Spallanzani e Albrecht von Haller,” in Commemorazioni Spallanzaniane... 1939, 111 (Pavia-Milan, 1939–1940), 116–118: R. Savioz. Mémoires autobiographiques de Charles Bonnet, de Genève (Paris, 1948): J. Senebier. Eloge historique d’Albert de Haller (Geneva, 1778): P. Vaccari, Storia della università di Pavia (2nd ed., Pavia, 1957), ch. 8, pp. 177–218: and G. S. Volta, “Nuovericerche ed osservazioni sopra il sessualismo di alcune piante,” in Memorie della reale accademia di scienze, belle lettere ed arti, Mantova, 1 (1795), 225–267.

The following works illustrate the significance of Spallanzani’s main scientific contributions. SPONTANEOUS GENERATION: C. Bastian, The Beginnings of Life, 2 vols. (London, 1872); L. Belloni, Le “contagium vivum” avant Pasteur (Paris, 1961); W. Bulloch, “Spontaneous génération and Heterogenesis,” in The History of Bacteriology (London, 1938, repr., 1960), ch. 4, pp. 67–125: H. Dale, Viruses and Heterogenesis. An Old Problem in a New Form (London, 1935), the Huxley lecture: J. T. Needham, Nouvelles observations microscopiques, avec des découvertes intéressantes sur la composition et la décomposition des corps organisés (Paris, 1750); and G. Pennetier, Un debat scientifique. Pouchet et Pasteur 1858–1868 (Rouen, 1907). REGENERATION, EMBRYOLOGY AND FECUNDATION: C. Bonnet, “Expériences sur la regénération de la tete du limacon terrestre,” in Journal de physique, 10 (1777), 165–179; Comte de Buffon (G. L. Leclerc), “Histoire des animaux,” in Histoire naturelle, 2 , pt. 1 (Paris, 1749); A. W. Meyer, The Rise of Embryology (Stanford, Calif., 1939), chs. 5, 9–11, pp. 62–85, 132–211: and J. Needham, A History of Embryology (Cambridge, 1934), 179–229. DIGESTION: D. G. Bates, “The Background to John Young’s Thesis on Digestion,” in Bulletin of the History of Medicine, 36 (1962), 341–362: J. Hunter, “Some Observations on Digestion,” in Observations on Certain Parts of the Animal Oeconomy (London, 1786), 147–188; R. -A. F. de Réaumur, “Sur la digestion des oiseaux,” in Académie des sciences (Paris, 1752), 266–307, 461–495; and J. R. Young, An Experimental inquiry into the Principles of Nutrition and the Digestive Process (Philadelphia, 1803), repr. with intro. essay by W. C. Rose (Urbana, Illinois, 1959). FLIGHT OF BATS: R. Galambos, “The Avoidance of Obstacles by Flying Bats: Spallanzani’s Ideas (1794) and Later Theories,” in Isis, 34 (1942), 132–140; D. R. Griffin, Echoes of Bats and Men (New York, 1955), 27–33, 87–88: and L. Jurine, “Experiments on Bats Deprived of Sight,” in Philosophical Magazine, 1 (1798), 136–140, trans. from Journal de physique, 46 (1798), 145–148. Spallanzani’s chief monographs were reviewed anonymously at some length in Giornale de’ letterati di Pisa (1774–1795).

Claude E. Dolman

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Lazzaro Spallanzani

Lazzaro Spallanzani

The Italian naturalist Lazzaro Spallanzani (1729-1799) was one of the founders of modern experimental biology.

Lazzaro Spallanzani was born in Scandiano on Jan. 12, 1729. He entered a Jesuit college at the age of 15 and later studied law at Bologna, but very early he became interested in physics and developed an overall knowledge of nature. He took orders in 1755 and is therefore often referred to as the Abbé Spallanzani. That year he began to teach logic, metaphysics, and classics at Reggio. In 1757 he was appointed to the chair of mathematics and physics at the university there; later he taught at the University of Modena.

In 1765 Spallanzani began publishing his numerous scientific works. Most of them are motivated by a philosophy of science which nowadays could be called reductionist, namely, a belief that most phenomena are reducible to physical and chemical explanation. In 1769 he accepted the chair of natural history at the University of Pavia, remaining at this post until his death on Feb. 11, 1799.

Spallanzani is well known for one of his major works on microscopical observation that concerned the systems of spontaneous generation, and was an attempt to disprove J.T. Needham's and the Comte de Buffon's theory in support of spontaneous generation. Although his experimentation was exact, and he did prove that some organisms can live in a vacuum for many days (anaerobiosis), his theory was not comprehensive enough. Thus Spallanzani did not succeed in establishing in a final way that the theory of spontaneous generation was wrong. He also did important work in embryology. He was an ovarian preformationist, and through his experiments with artificial fertilization using filtered semen he pointed out the need for the physical contact between the spermatozoa and the ovule. He thus disproved the fertilizing power of the seminal fluid. Yet he did not fully understand the process, and in plants he described fertilization as being effected by the spermatic vapor of the pollen and not by any of the visible parts of it. In his studies on regeneration of animals he practically established the modern lines of animal morphology.

Spallanzani also worked on problems of circulation, gastric digestion, respiration, the hearing of bats, the electricity of torpedo fish, and the reproduction of eels. As a result of these studies he gave experimental proof of the action of gastric juice on foodstuffs. He theorized that this action was not putrefaction or vinous fermentation, as others had thought, but acid fermentation; however, he was unable to isolate acid from the gastric mixture. His experiments on respiration provided evidence that tissues use oxygen and release carbon dioxide.

Especially noteworthy is the long trip Spallanzani undertook in Sicily and the neighboring volcanic areas. With systematic measurements and exact physical methods he established that there was nothing mysterious about the fire in the volcanoes; on the contrary, the same physical laws which apply on the surface of the earth are the ones which create volcanoes and which are acting in the heart of the earth. He succeeded in measuring the heat in one of the volcanoes and expressing it in degrees Fahrenheit, which were used in regular terrestrial measuring. His description of these areas is rich—not only in describing nature but also the social habits, customs, and crafts of the inhabitants and the ways of primitive science.

Further Reading

Spallanzani's life and career are well covered in Paul De Kruif, Microbe Hunters (1926), and Wade W. Oliver, Stalkers of Pestilence: The Story of Man's Ideas of Infection (1930). Spallanzani is also discussed in Joseph Needham, A History of Embryology (1934; 2d ed. 1959), and Arthur William Meyer, The Rise of Embryology (1939). □

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Spallanzani, Lazzaro

Lazzaro Spallanzani (läd´dzärō späl-läntsä´nē), 1729–99, Italian naturalist. He was professor at the universities of Modena (1763–69) and Pavia (from 1769). Spallanzani studied regeneration, fertilization, and the digestive action of saliva; using heat-sterilized cultures, he performed experiments that disproved J. T. Needham's theory of spontaneous generation.

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