Pierre Demours was born at Marseilles in the early part of the eighteenth century, began the study of medicine at Avignon, and then went to Paris for the completion of his professional training. He received his doctor’s degree, however, at Avignon in 1728, probably because the graduation fees in the latter city were not so large as those required in Paris. At a still later date he returned to the capital for the further prosecution of his professional studies, and while there he was given the appointment of Assistant to Duverney, the celebrated anatomist, who at that period, despite his advanced age (eighty years), was still actively engaged in research work. Two years later, upon Duverney’s death, Demours was invited to accept the associated positions of Demonstrator and Custodian of the Cabinet of Natural History at the Jardin du Roi. He had occupied these positions only a short time when Jean-Louis Petit, the celebrated French surgeon, who had observed the excellent character of the work performed by Demours, advised him to direct his studies more particularly to the anatomy and maladies of the eyes. Demours was quite ready to accept this advice, and thus it came about that in a few years he acquired considerable reputation as a successful practitioner in affections of the eye, a reputation which he continued to hold up to the time of his death on June 26, 1795.

Among the contributions which Demours made to the literature of ophthalmology the following deserve to receive special mention:—

Letter to Petit giving the report of an eye complication that developed as the result of an inoculation with the virus of small-pox; together with an account of some new observations relating to the anatomy of the eye and a few general comments on diseases of that organ; Paris, 1767.

A new series of remarks upon certain features in the anatomy of the cornea; Paris, 1770.

Observations on the structure of the corpus vitreum; Paris, 1741.

Observations on the cornea; Paris, 1741.

Dissertation on the mechanism of the movements of the pupil and on certain characteristics of the fibrae rectae of the uvea, in “Mémoires des Savans Étrangers,” tome II.; and the following articles in the “Journal de Médecine” edited by Vandermonde: “On an affection of the eyes which sometimes develops after a perfectly faultless cataract operation (extraction),” in tome XVI.; “Reply to Monsieur Descemet’s article on the cartilaginous layer of the cornea,” in tomes XXXI. and XXXIII.

Jean Descemet, born at Paris on April 20, 1732, was the pupil and friend of Duhamel-Dumonceau, one of the greatest teachers of that period and an enthusiastic scientist, but not a physician. Vicq-d’Azyr says that the list of the papers which he published during his lifetime (he was eighty-two years old at the time of his death) is very long and reveals the fact that he was interested in a great variety of topics, the majority of them relating to commerce, the arts, vegetable physiology, agriculture, and marine questions. To Descemet the influence of such a powerful mind, so enthusiastic and yet so precise in all its operations, could not fail to have been very great, and one of its earliest effects was to lead him to take a strong interest in botany and in anatomical research work. His graduation thesis, which—in accordance with the prevailing custom—he publicly defended early in 1758, dealt with the subject of the minute anatomy of the cornea and the lens. As the investigations which he made in regard to these important structures were strictly original, the scientific authorities accorded to him the honor of having his name attached to the membrane which lines the internal face of the transparent cornea, and which at the same time envelopes the aqueous humor. The reason why this membrane was selected by preference was this: Descemet was believed to have been the first person to describe in great detail this previously unknown structure. Demours, in 1767, published an article in which he claimed that the honor of this discovery belonged to him and not to Descemet. I cannot pretend to decide upon the justice of this claim; but, so far as I am able to learn, nobody has in modern times seriously disputed the propriety of retaining the name “Descemet’s membrane.”[[25]]