(b. Kis-Kér, Hungary [now Bačko Dobro Polje, Yugoslavia], 20 August 1810; d. Paris, France, 14 November 1898)
mcirobiology, medical mycology, parasitology.
At the time of his death Gruby was known mainly as an eccentric physician famous for the extravagant cures prescribed for his distinguished patients, who had included Frédéric Chopin, Alexandre Dumas père, Heinrich Heine, Alphonse Lamartine, Alphonse Daudet, George Sand, Ambroise Thomas, and Franz Liszt. These prescriptions were actually clever applications of psychosomatic medicine. It was only slowly realized that in the short period of his scientific activity Gruby had made very original and important contributions to science—indeed, he founded an important branch of modern medicine, discovering the dermatomycoses, a group of skin diseases caused by parasitic lower plants.
Gruby was one of seven or eight children of a poor Jewish peasant in a village of Baczka, a fertile district of southern Hungary. Although in his birthplace he could have received only an elementary education, he very early showed great interest in reading and studying. He received his first instruction in secular knowledge from a medical student who worked as a substitute teacher in Kis-Kér and lodged in Gruby’s father’s home. Gruby left Kis-Kér about 1824 or 1825 to seek further education in Pest. His early years had been marked by great poverty, hardship, and prejudice, although some of the reported stories may be more fiction than truth. His great talent and determined pursuit of his aim enabled him to succeed, against all the odds, in completing his secondary studies at the Piarist Gymnasium in Pest. In 1828 Gruby went to Vienna to study medicine. According to the list of medical students of 1836 he was then in the fifth year of his studies. He passed the first examination on 13 February 1838, the second on 18 March 1839, and graduated on 5 August 1839.
The time he took for his studies seems unusually long for a gifted student, but in order to earn a living Gruby seems to have acquired some special technical knowledge: he is reported to have built himself an accurate clock and a microscope which was, for the time, an excellent instrument. In his microscopic studies Gruby was encouraged and guided by two young teachers who were beginning their distinguished careers at the Vienna medical school: Joseph Berres, from 1831 professor of anatomy, and Karl Rokitansky, from 1833 prosector and a year later associate professor of pathological anatomy. Some of Gruby’s early microscopic observations on pathological morphology were included in his dissertation, which contains microscopic observations (with 103 illustrations) on the pathology of body fluids—mucus, sputum, pus, pseudomembranes, coagula, and saliva— and compares pathological with normal findings. His attempt at microscopic differentiation of pus from other pathological substances was a careful, original investigation in a new field of medicine. Gruby demonstrated, among other things, that every one of the studied body fluids contained living elements (leukocytes). He republished his dissertation as the first part of a larger treatise on microscopic pathology, but the other planned parts never appeared.
Gruby also made preparations to be sold to various institutions and gave courses in microscopy, which enabled him to meet many visiting foreign physicians, such as William Bowman and P. J. Roux. It was Roux who suggested to Gruby—who could not find a suitable position because he refused to give up his religion—that he move to Paris, the great center of medical learning. Microscopy was little practiced there, and thus Paris offered a promising field for an experienced young man.
Gruby settled in Paris in 1840. Assisted by friends, he worked in the Foundling Hospital under the distinguished pediatrician Jacques François Baron and, urged by some foreign students, he began to give courses in microscopic anatomy and pathology which were attended by Claude Bernard, Francois Magendie, Henri Milne-Edwards, Pierre Flourens, and many foreign scientists.
At this time Gruby began to announce his discoveries of various microscopic fungi that produce skin diseases. In 1841 he found a fungus in favus, a contagious skin disease marked by round yellow crusts resembling honeycomb, usually situated over hair follicles and accompanied by intense itching. The following year he described Trichophyton ectothrix, a microscopic cryptogam, found at the roots of a man’s beard, which caused the disease Sycosis barbae. Shortly afterward he discovered Oidium albicans (Monilia albicans), the cause of thrush in infants. In 1843 Gruby described another fungus, which he called Microsporum audouini, in honor of Jean Victor Audouin. In man Microsporum causes a form of tinea (ringworm) that is also called microsporia or Gruby’s disease. Another form of ringworm, caused by Trichophyton tonsurans, was discovered and described by Gruby in 1844. The cause of favus, Achorion schoenleini, was first described by J. L. Schönlein, who was not certain whether it was the cause or a manifestation of the disease. Gruby showed that the disease could be produced experimentally in man or animals by inoculating the specific mold. His clinical descriptions were generally inadequate, but his descriptions of the microscopic features were so excellent that when his findings were later rediscovered and confirmed, not much could be added to his original reports. The idea of a plant parasite as a cause of disease in man was something quite new in the era before Pasteur; and Gruby was responsible for the firm establishment of this conception by his findings and experiments, against the doubts, opposition, and ridicule of many contemporary physicians.
In 1843 Gruby discovered an animal parasite in the blood of the frog that he called, because of its corkscrew shape, Trypanosoma; the name has been used for this important genus ever since. In the same year he described, in association with his friend Onésime Delafond, professor at the veterinary school at Alfort, another parasitic hematozoon in the dog microfilaria. They also showed (1852) that the disease could be induced in a healthy dog by intravenous transfusion of defibrinated blood from an infected animal. In 1859 Gruby described and depicted a parasitic mite (Acarus) producing skin disease called Erythema autumnale.
In 1847–1848, in the early period of general anesthesia administered by inhalation, Gruby made experiments on animals with ether and chloroform, which contributed to the knowledge of their effects on several bodily functions. He also emphasized the higher toxicity and quicker action of chloroform as compared with ether.
After 1845 Gruby published only a few papers, eventually spending all his time and energy on his medical practice. The cause of his loss of interest in scientific endeavor remains unknown,
I. Original Works. Gruby’s inaugural diss., Observationes microscopicae ad morphologiam pathologicam (Vienna, 1839), repub. in 1840 with the subtitle Morphologia fluidorum pathologicorum, tomi primi, pars prima, seems to be his only book on science. He published over 30 short papers, 21 of them in Comptes rendus hebdomadaires des séances de l’Académie des sciences, 13–34 (1841–1852). Six of them were written in collaboration with O. Delafond, and about 20 date from 1841–1845. Some of Gruby’s papers were soon translated into German or English. Six of them, representing the foundation of medical mycology, were published “as a monument aere perennius of Gruby’s scientific achievement” in an English trans. by S. J. Zakon and T. Benedek: “David Gruby and the Centenary of Medical Mycology 1841–1941,” in Bulletin of the History of Medicine, 16 (1944), 155–168. A bibliography of Gruby’s works was collected by R. Blanchard (1899) and is included (with some additions) in the biographies by L. Le Leu (1908), A. P. M. Salaun (1935), and B. Kisch (1954).
II. Secondary Literature. A full biography is B. Kisch, “David Gruby’ (1810–1898),” pt,. 2 of “Forgotten Leaders in Modern Medicine,” in Transactions of the American Philosophical Society, n. s. 44 (1954), 193–226. Of the older appreciations the most important are R. Blanchard, “David Gruby (1810–1898),” in Archives de parasitologie, 2 (1899), 43–74; L. Le Leu, Le Dr. Gruby. Notes et souvenirs (Paris, 1908), a volume of notes and recollections by Gruby’s last (from 1888) private secretary; and A. P. M. Salaun, La vie et l’oeuvre de David Gruby (Bordeaux, 1935). There are several short biographies, such as T. Rosenthal, “David Gruby (1810–1898),” in Annals of Medical History, n. s. 4 (1932), 339–346; and several appreciations of his discoveries in the field of dermatomycoses: E. Podolsky, “David Gruby (1810–1898) and the Fungus Growth,” in Medical Annals of the District of Columbia, 26 (1957), 24–26;60; J. H. Rille, “David Gruby,” in Dermatologische Wochenschrift, 83 (1926), 512–526; and J. Théodoridès,“L’oeuvre scientifique du Docteur Gruby,” in Revue d’histoire de médecine hébraïque, 27 (1954), 27–38, 138–143.
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