James Dwight Dana
Dana, James Dwight
Dana, James Dwight
The son of James Dana, a saddler and hardware merchant, and Harriet Dwight, Dana grew up in a respectable, churchgoing family of modest means. At Yale College, Benjamin Silliman gave direction to his interest in natural history, and under his tutelage Dana developed a consuming interest in geology, particularly mineralogy. Upon graduation, like other college–trained American students of science, he faced the choice of a livelihood with little prospect that it would lie in science, for aside from the occasional post in college teaching, the opportunities for a scientist without independent means to practice his profession were all but nonexistent. Delaying the decision, Dana chose to spend his Wanderjahr (1833–1834) as school-teacher to midshipmen aboard the U. S. S. Delaware. On this service he observed his first volcano and made it the subject of his first scientific paper, “On the Condition of Vesuvius in July, 1834,"1 Two years later he was saved for science by Silliman’s offer of an assistantship in the chemical laboratory at Yale, then confirmed in his vocation by the invitation to serve with the Wilkes expedition of 1838–1842, having been recommended by his friend and contemporary, the botanist Asa Gray.
An adventure in cultural patriotism, this elaborate enterprise was to be one of the great events in the history of science in the United States. The expedition circled the globe, charting and conducting natural history surveys in Polynesia and confirming along the way the existence of an antarctic continent. To the scientist in a nation committed to the principles of self–help and minimal government, it offered an unprecedented opportunity to practice his profession under government patronage, and it was the making of Dana’s career. Although accounting himself a mineralogist (his first book, A system of Mineralogy, was published the year before the expedition sailed), Dana shipped as a geologist, and when the conchologist Joseph P. Couthouy was dismissed from the squadron at Sydney, he became marine zoologist as well. As he “served the cruise,” sharing all the perils except the coasting of Antarctica (he remained in Australia and New Zealand with the other “scientifics”), for four years the world was his laboratory. The experience gave Dana a competence in natural history matched in his own day only by Darwin’s on the Beagle. It inspired his lifelong interest in both volcanic and coral phenomena and perhaps his peculiar approach to geology as well, for he ever afterward sought to treat the earth as a geological unit.
Dana’s interpretation of these phenomena was profoundly influenced by his religious enthusiasms, for although a model of piety as a child, he had undergone a particularly rigorous religious experience on the eve of sailing. It made him a prissy shipmate. It also predisposed him to comprehend microcosm and macrocosm in a sweeping scientific conception of natural phenomena.
After weathering an unfortunate controversy with Couthouy, whom he too hastily charged with plagiarism, Dana devoted the fourteen years between the expedition’s return and his assumption of the duties of Yale’s Silliman professorship of natural history in 1856 to writing the expedition reports entitled Zoophytes, Crustacea, and Geology. The whole subject of zoophytes, the plant–like animals now called coelenterates, and the corals in particular, was new to science. Traditionally the preserve of poets and clergymen, it came laden with conceits and preachments. Although the coral structures actually afforded the most spectacular example of the role of the organism in modifying the earth’s crust, it was beyond the comprehension of many that these “animalcules,” some of them microscopic, could build islands and reefs, which were ascribed instead to tropical lightning, to “the electric fluid engendered by sub–marine and other volcanoes” (notions which Dana described tartly as “the first and last appeal of ignorance”), and to fishes that labored diligently with their teeth. Many who were willing to credit the polyps saw them as “busy little builders of the deep,” exemplifying selfless and patient industry as well as the benevolence of the Creator in providing stone flowers for man’s delight and seawalls for his protection. Occupying the border zone between the animal and vegetable kingdoms, they had been transferred by general consent to the animal kingdom only during the past century. Dana early perceived the task that lay before him: disabuse the poets, enlighten the preachers, and put the subject on a scientific basis.
His observations on coral phenomena appeared in Zoophytes and Geology. The former was a monumental work that cost Dana a vast amount of labor, both because the subject had been so little known (203 of the expedition’s 261 actinoid zoophytes and 229 of the 483 coral zoophytes were unknown to science, and even more were unknown in the living state)and because coral animals and the Actiniae (such as the sea anemone, a group that, although related to the coral zoophyte, makes no coral) are among the most difficult groups of the animal kingdom to classify systematically. The work was also a milestone in science, for Dana not only classified the animalcules but also elucidated their physiology, both individual and communal, and their ecology. As Asa Gray predicted in his review, the report long remained the standard authority on the subject and retains its validity after the passage of more than a century, for the large divisions Dana defined and a majority even of his species are still accepted. With the publication of Zoophytes, Dana became the source for all that was known of coral zoophytes and the Actiniae.
The popular appeal of these relatively specialized reports was remarkable, and when Dana’s observations on coral phenomena were printed as a separate book, Corals and Coral Islands, it passed through three editions in his lifetime. While it might be said that the audience for such a topic was forgathered, the book’s popular success owed much to Dana’s remarkably fine style of writing and, not least perhaps, to the penchant he shared with the preachers and poets for perceiving a design in nature that was flattering to man. Tracing the history of the coral plantation—the shrubs and trees which “stand and wave unhurt in the agitated waters” and are the secretions of the thousands of polyps that “cover the branches, like so many flowers, spreading their tinted petals in the genial sunshine, and quiet seas, but withdrawing when the clouds betoken a storm"—he found that when the polyps die, minute encrusting corals attach themselves to the surface to protect the structure from erosion by the sea until “Finally, the coral becomes subservient to a still higher purpose than the support of polyps and nullipores,” and the debris produced by wave action upon the reef settles into the crevices to produce a solid rocky base that gradually becomes one of “’the sea–girt isles’… the coral polyps now yielding place to the flowers and groves of the land, which fulfill their end in promoting the comfort and happiness of man.”2
Dana had seen his first coral island, Clermont Tonnerre, when he was twenty–six; and even before the squadron reached Sydney, he had carefully observed the three great types of coral structures: atolls(which Charles Lyell was viewing as merely the crests of submarine volcanoes encrusted with coral), barrier reefs, and fringing reefs. Consequently he was well equipped to address himself to the problem of why there were different and well–defined formations. It was Darwin who showed him the way. Shortly after reaching Sydney in 1839, Dana chanced upon a newspaper statement of the theory Darwin had formed to explain the origin of atolls and barrier reefs. It “threw a flood of light over the subject.”3 Dana had not seen the Gambler Islands on the southeastern fringe of the Tuamotus, which had given Darwin the inspiration for his theory; but the Fijis, where the Americans remained three months, presented similar phenomena i greater variety and on a grander scale and provided the opportunity to test the theory.
Darwin sought to explain the three types of island formations as so many stages in the evolution of the atoll, with subsidence the responsible agent. In areas subject to subsidence, the fringing reef, which lies close to the once–volcanic island and parallel to it, continues to grow upward and also, because the mote favorable conditions for coral growth obtain at the reef’s outer edge, outward until, separated from the shore by a lagoon, it becomes a barrier reef. As subsidence proceeds and the island is completely sub–merged, the barrier reef becomes an atoll. Subsidence like wise explained the great depth of many reefs, hitherto something of an anomaly in view of the discovery that the animal could not subsist below a depth of 180 feet. Subsidence granted, the reef could be of any depth so long as its upper portion remained above that critical depth. The theory was simple, ingenious, grand, and, as Darwin noted, it explained “a phenomenon otherwise inexplicable.” Unfortunately, it lacked a firm basis without independent confirmation that subsidence had indeed taken place, and Darwin despaired of detecting “a movement the tendency of which is to conceal the parts affected.”4 Nevertheless, he made the attempt by plotting the geographical distribution of coral reefs and volcanic areas, for since he associated barrier reefs and atolls with subsidence, so he associated volcanoes with rising areas and fringing reefs with areas either rising or stable. The result showed that areas of barrier reefs and atolls were widely separated from those of fringing reefs and volcanoes.
Dana’s own observations fully bore out Darwin’s theory and, although they passed unnoticed for many years, led him to independent confirmation of the idea that barrier reefs were the result of subsidence. In 1839 he had ascended Mount Aorai, Tahiti’s second peak and, looking out across the island, realized that the deep gorges that had made the climb so difficult were the result of stream erosion. What effect, he asked himself, would Darwin’s subsidence produce here? Deep bays at first, then fjords. Examination of the contours of other islands convinced him that those within barrier reefs generally were em bayed. The irregular shoreline was the result not of the action of waves and currents, as Darwin apparently assumed (for such action would tend to obliterate irregularities by filling bays and inlets), but of sub aerial erosion of a once–high island. It provided the b best evidence yet in support of Darwin’s subsidence theory. On reading through Dana’s section on coral structures. Darwin was "astonished at my own accuracy!!" and found Dana’s support of his own theory “wonderfully satisfactory.”5
But on the matter of the chart of areas of subsidence and elevation that Darwin had plotted, Dana took him sharply to task. To be sure, coral islands evolved as Darwin said they did, through subsidence, but that did not mean that the vast areas of coral islands or even individual islands were still subsiding, as he had suggested. On those he himself visited, Dana found evidence of elevation (deposits of coral material above the level where they were presently forming, and on islands not coral the presence of sedimentary deposits inter stratified among layer of other rocks constituting the hills) varying from one foot at Tahiti to 600 feet at Guam. As Dana saw it, Darwin had placed too much reliance on changes of level in different regions, concluding that areas of active volcanoes were areas of elevation and ascribing to elevation the absence of reefs. Dana pointed out that these were no proofs against subsidence having taken place, for a variety of causes—the heating of the sea by volcanic activity, for example—might delay coral growth or percent it entirely, as by too rapid subsidence or the flow of continental waters. And the absence of reefs was no proofs of elevation. He cited the island of Maui, which had no reefs on its large part, the scene of recent volcanic action, but did have reefs on the other end, where the fires were long since extinguished, and suggested that one end had been undergoing elevation and the other subsidence.
Still, Dana’s differences with Darwin were not great. His observation served to refined and correct particulars of Darwin’s theory rather than to supplant it. Having provide independent confirmation of the English naturalist’s subsidence as a condition necessary to the existence of barrier reefs and atolls, he could address himself objectively to the matter of their distribution. Dana observed that “two hundred islands have subsided in the Pacific, which, had there been no corals, would have disappeared without a record.” The coral areas were confined within rather precise limits—the isothermal lines belting the earth that were determined by ocean currents—for the creatures could not live where the water temperature fell below sixty–six degrees. Since each barrier reef or atoll was assure sign of subsidence, it was clear that a vast area of the Pacific, extending from the Tuamotus to the western Carolines, had once subside. Dana concluded that subsidence increased from south to north or north–eastward and was greatest between the Navigators and the Hawaiian Islands. Since the length of the area amounted to about a quarter of the circumference of the globe and its width to about that of the North American continent, Dana reasoned that the movement had surely constituted “one of the great secular movements of the earth’s crust” and must have affected the entire sphere, “for all parts, whether participating or not, must have in some way been in sympathy with it.” Probably the downward movement in the tropical Pacific involved the warmer latitudes of all oceanic areas (witness the progressive easterly diminution in the size of the West Indies until they disappear and the Atlantic becomes a blank) and was answered by the elevation of the northern continental lands in the glacial era. Dana’s treatment of the subject was nothing if not thorough. Examining it with the eye of both the biologist and the geologist, he linked the tiniest of the coral polyps to the grand movements of the earth’s crust.
Darwin’s identification of volcanic regions with areas undergoing elevation and his own independent observation of the limits that volcanic activity placed on coral growth whetted Dana’s interest in volcanism. He visited many volcanic regions while with the expedition and at the Hawaiian group took up the subject in earnest, becoming the first of a long line of geologist to make detailed observations of Mauna Loa and Kilauea. Recognizing that a history of their activity was essential to an understanding of the processes involved, Dana gathered all the information available since the first recorded eruption in 1789, continued for the rest of his life to collect data by correspondence, and at the age of seventy–four went out to view them once again, then published his book on the subject.6 Although not particularly successful in the attempt to determine their peiodicity, he was able to establish fairly clear–cut steps in the volcanic process.
Audacious by nature and emboldened by his unparalleled opportunities for observation while with the expedition, on his return Dana promptly attacked the theory of Christian Leopold von Buch that volcanic cones were formed by extrusion from below in the form of a dome pushed upward by hot steam. If the dome cooled and solidified, it remained without a crater but, if the steam burst through, the material of the dome fell inward to form the typical crater. Siding with the English geologists Lyell and George J. P. Scrope, Dana denied that craters were formed in this way, insisting, rather, that the cones were produced by the accumulation of ejecta from successive eruptions. He recognized in the gently sloping Hawaiian volcanoes a kind of eruption different from that of steep Vesuvius and ascribed the shape of the former to a quiet outpouring of liquid lava and that of the latter to eruptions of more viscous material.
Dana’s ascent of Mount Aorai served him well in volcanology, as it did in his study of corals, and he was able to show that the present rough surface of Tahiti, once a smooth dome like Mauna Loa, was due to stream erosion. At a time when that process was only partially understood, his report, one of the earliest examinations of the erosion of a volcanic cone, called attention to its importance in shaping any land mass.
Dana’s chapters on the Hawaiian Islands elucidated many points of volcanology, but to his own way of thinking he had cleared up only a very few sequences in the great and continuing process of the earth’s formation. The subject of geographical distribution seemed naturally to lead to macrocosm, and Dana went on to link the geological implications of his study of corals to his volcanology. The ocean bottom in which he detected great subsidence was, he reasoned, at one time the most intensely heated part of a cooling earth and the last to solidify. Consequently it had undergone the greatest contraction. This vastly deepened the ocean basins, thrust up the continents, and formed the great mountain chains along their borders.
The picture that emerged was that of the earth of the present, and indeed Dana’s concept of the permanency of the continents and the ocean basins, first presented in his Geology of the expedition, was to influence geological thought profoundly. In the emphasis he placed on this concept and the significance he accorded stream erosion, Dana outdid even Lyell in uniformitarianism, the great principle that was liberating geologists from the bonds of miraculous intervention. He did not hesitate to pull the master up sharply when he lapsed from principle, as when, promptly on the expedition’s return, he announced his disagreement with Lyell on the source of the heat that metamorphosed sedimentary deposits on the ocean floor.
Yet, like most other uniformitarians, Dana was a catastrophist in biology, committed to the notion that entire species and genera were periodically destroyed and new ones created—man most emphatically excepted. His work in classifying the expedition specimens raised problems in the delineation of species, and time and again in his 1,600-page report Crustacea he remarked on the “difficulties in the way of arriving at natural subdivisions…. Nature had made her fields without fences” but only “mountain ranges” and “gentle gradations.” He considered the problem of geographical distribution of species and noted that the obvious explanation was either migration or local creation. In doubtful cases he even presented a perceptive argument for migration—then rejected it for local creation: “There characteristics are of no climatal origin,” he remarked in one such passage. “They are the impress of the Creator’s hand…”7 Like most of this contemporaries, he was simply unable to rid himself of the conventional view of the purposiveness of nature.
As accurate in classification as Darwin and fully as able a systematist, Dana could not help but discern change and, as he interpreted it, progress; and the present problems of classification that marked his path through the expeditions’s Crustacea drove him to devise a theory of his own that would describe the progress observed, n if it could not explain it without recourse to supernatural intervention. “Cephalization,” as he called it, was the release, from lower species to higher, of the organs of locomotion to the service of the brain, and it provided a measure of the intelligence of the species. Increasingly, mind became dominant over body, and reflective and moral faculties appeared.8 But the concept was no more than a further elaboration of the design Dana perceived in nature. It was his determined attempt to render purposive the succession of catastrophes and new creations that otherwise would have seemed random and idiotic.
Within limits determined at their utmost by extra–scientific considerations, Dana remained remarkably open–minded. In 1856 he opened a vigorous defense of science against the bibliolaters in the pages of the Bibliotheca sacra,9 and when, that year, Drawin wrote him to say, “I am becoming, indeed I should say have become, sceptical as to the permanent immutability of species,” and went on to express the hope that Dana would give him credit “for not having come to so heterodox a conclusion without much deliberation,"10 Dana appended to a long article of his own on the species problem a word of caution: “We should give a high place in our estimate to all investigation tending to elucidate the variation of permanence of species, their mutability or immutability…”11
Dana was unable to give any kind of place to the Origin of Species when it appeared, for that year his health broke down completely, and it was some years before he read the book. He kept the pages of the American Journal of Science, of which he had become an editor in 1846, open to Asa Gray, whose main article was a reply to Agassiz’s scathing critique of the Origin in the same journal. Gray was rigorously defending the Darwinian doctrine (though with a critical eye), but Dana would have none of it himself. The first public indication of any change in his views appeared in the 1874 edition of his Manual of Geology, where, of the concepts he thought “most likely to be sustained by further research,” he accorded first place to the proposition that “The evolution of the system of life went forward through derivation of species from species, according to natural methods not yet clearly understood, and with few occasions for super–natural intervention.”12
Dana was the principal exponent, if not the originator, of the geosynclinal–contraction hypothesis of mountain building. In the later editions of the Manual of Geology, he proposed that the forces producing mountains acted laterally and unequally form two opposite directions, that a relatively thin rigid crust overlies a densely viscid or pasty region of great thickness, and the globe is undergoing continued refrigeration. The contraction beneath the crust was considered to be much greater than the contraction within the crust. The result would be the formation of gigantic linear depressions (the geosynclinals of James Hall) with continued sedimentation in the geosynclinals.
Gravity, together with lateral pressure or thrust of the crust due to the unequal contraction of the sub–crustal material, would produce folded mountains. The Appalachian structures described by W. B. and H. D. Rogers would be typical example.
Dana relied for much of his physical information on the work of G. H. Drawin. Accompanying the formation of the geosynclinal there would necessarily be a parallel geanticlinal. Refusion and partial mobilization of the bottom of the geosynclinal, as discussed theoretically by Herschel, would lead to igneous activity and the action of vapors and liquids, as well as a wide range of other geological processes. Massive evidences from the extensive, regional geologic surveys in the western United States and the Alps were mustered by Dana into a coherent and cohesive geological system which with minor modification remained the guiding theoretical framework of geodynamics through the first quarter of the twentieth century.
A member of the first generation of American specialists in science, a generation that contributed much toward making a profession of science, Dana also belonged to the first generation to be caught up in the warfare between science and revealed religion. Committed to both, he strove to retain a footing in two worlds inexorably drifting apart. But the rest of his life was a progressive surrender to Darwinism, although he continued to insist on those few occasion for supernatural intervention, particularly in the evolution of man, and curiously—but perhaps predictably, from his youthful response to the scenes of savagery in the Pacific—his acceptance of the social Darwinism that was becoming fashionable in the closing years of his life was a good deal more prompt.
Dana retired from Yale in 1890 at the age of seventy–seven. Thereafter the books and scientific papers came some what less frequently. In his lectures generations of students and of Americans who took an interest in the things of nature, great and small, had the opportunity to join him on the great adventure of his youth. “If this work gives pleasure to any,” he remarked toward the close of his life in the third edition of his book on corals, “it will but prolong in the world the enjoyments of the ‘Exploring Expedition.’”13
Dana was slight of figure and, from frequent illness during the last three decades of his life, frail in health. He liked to write hymns and love songs for the guitar, and although an active participant in the affairs of the American Association for the Advancement of Science (and its president in 1854) and for many years the commanding figure among the world’s geologists, he preferred the tranquillity of his domestic life to public appearance. Of the honors conferred upon him Dana was perhaps most gratified by the remark of ex–President Thiers of France that he had been much strengthened in his faith by the writings of “Monsieur Dana, a professor at New Haven.”14
1.American Journal of Science, 27 (1835), 281–288.
2. Dana, Zoophytes, pp. 83, 84.
3. Dana, Corals and Coral Islands(1890), p. 7.
4. Charles Darwin, The Structure and Distribution of Coral Reefs (London, 1896 [first pub. 1842]), p. 125.
6. Dana, Characteristics of Volcanoes.
7. Dana, Crustacea, I, 45, 158.
8. Dana, “On Cephlization,"
9. Dana, “Science and the Bible,"
10. Sanford, “Dana and Darwinism,” p. 534.
11. Dana, “Thoughts on Species,” p. 871.
12. Dana, Manual of Geology (1874), pp. 603–604.
13. Dana, Corals and Coral Islands (1890). preface.
14. Gilman, op. cit., pp. 357–358.
I. Original Works. Dana’s writings include A System of Mineralogy (New Haven, 1837); United States Exploring Expedition during the Years 1838, 1839 1840, 1841, 1842, Under the Command of Charles Wilkes, U. S. N Zoophytes (Philadelphia, 1846);… Geology (Philadelphia, 1849);… Crustacea, 2 vols. (Philadelphia 1852); “Science and the Bible: A Review of ‘The Six Days of Creation’ of Prof. Tayler Lewis,” in Bibliotheca sacra, 13 (1856), 80–130, 731–756; 14 (1857), 388–412, 461–524; “Thoughts on species.,” ibid, 14 (1857), 854–874; Manual of Geology (Philadelphia–London, 1862); “On Cephalization,” in New Englander, 22 (1863), 495–506; Corals and Islands (New York, 1872); and Characteristics of Volcanoes (New York, 1890).
The largest collection of Dana’s papers is at Yale University. Some fifty pieces are at Harvard, and other letters from his extensive correspondence are to be found at the American Philosophical Society, the University of Rochester, and the University of Illinois. A representative selection, together with a lengthy if not entirely complete bibliography, appears in Gilman’s biography.
II. Secondary Literature. See the following, listed in chronological order: Daniel C. Gilman, The Life of James Dwight Dana (New York–London, 1899); J. Edward Hoffmeister, “James Dwight Dana’s Studies of Volcanoes and of Coral Islands,” in Proceedings of the American Philosophical Society, 82 (1940), 721–732; Harley Harris Bartlett, “The Reports of the Wilkes Expedition, and the Work of the Specialists in Science,” ibid., 691–705; Ann Mozley, “James Dwight Dana in New South Wales, 1839–1840,” in Journal and Proceedings of the Royal Society of New South Wales, 97 (1964), 185–191; and William F. Sanford, Jr., “Dana and Darwinism,” in Journal of the History of Ideas, 26 (1965), 531–546.