GERHARD 433 GESNER usually accorded the credit of the first accurate clinical study of tuberculous meningitis." Above all he avoided any dependence on books and relied chiefly on personal observation and study. His thoughtful virorks on pediatrics are now little known, but the essential part of them still benefits the physician of to-day. In 1833 he went back to Philadelphia and became resident physician to the Pennsylvania Hospital and while there demonstrated the common continued fever of the United States to be identical with the typhoid he had studied in the wards in Paris. When in 1836 typhus broke out in Philadelphia he had opportunities of studying hundreds of cases and showed the identity of the disease with that seen in Edinburgh and the dissimilarity of both to typhoid. The honor of the discovery has been divided between Perry of Glasgow (1836), Lombard of Geneva (1836), Gerhard and Pen- nock of Philadelphia (1836), Shattuck of Bos- ton (1836), and others, but according to Osier, Gerhard's papers in the American Journal of the Medical Sciences, 1837, are the first in any language which give a full and satisfactory account of the clinical and anatomical dis- tinctions we now recognize. Gerhard's training made him specially de- sired as clinical lecturer at the Philadelphia Hospital, and he soon had a reputation in diseases of the heart and lungs. At his lectures students saw that truth was his ob- ject, not display. An attack of typhiod fever in 1837 hindered work and left him broken in health, so that a visit was made in 1843 to Europe. In 1868 he retired after a busy life and on April 28, 1872, Philadelphia lost one of her most genial, kindly and clever physicians. He held among other appointments the post of resident physician to the Pennsylvania Hos- pital, 1834; assistant professor institutes of medicine, University of Pennsylvania, 1838; visiting physician Pennsylvania Hospital, 1845 ; member of the Philadelphia Medical Society, College of Physicians, American Philosophical Society, and president of the Pathological Society. Among his writings are found : "Observations on the Cholera in Paris," 1832 (with C. W. Pennock) ; "On the Typhus Fever Which Occurred in Philadelphia in 1836, Showing the Difference between This . . . and Typhoid," Philadelphia, 1837; "Diagnosis, Pathology and Treatment of Diseases of the Chest," Philadelphia, 1842. Davina Waterson. Hist, of Med. Profess, of Phila., F. P. Henry, Chicago, 1897. Influence of Louis on American Med., Wm. Osier, Johns Hopkins Hospital Bulletin No. 77, 1897. Memoir of W. W. Gerhard, T. StewardsDn, IS74. Gesner, Abraham (1797-1864). Abraham Gesner, a descendant of that "very famous naturalist and author," Konrad Gesner, of Zurich, Switzerland (1516-1565), was born at Cornwallis, Nova Scotia, May 3, 1797, and died in Halifax, Nova Scotia, April 29, 1864. His father, Col. Henry Gesner, was a native of New York, and served during the Revolu- tionary War on the royaUst side, subsequently settHng in Cornwallis. Young Gesner had but little opportunity of securing a good general education, but he had that vigor and activity of mind which find a way to intellectual achievement in spite of difficulties. A "self-made man" in general learning, he early took to reading the book of nature at first hand in the rocks and min- erals, fauna and flora, of his native land, and throughout life, geology, mineralogy, and the chemistry connected therewith were his fa- vorite studies. By the time he was twenty he had made considerable advance in these sub- jects, and eagerly grasped at an opportunity afforded him of visiting the West Indies and part of South America that he might extend his scientific knowledge by an examination of the earth and its products in other countries than Nova Scotia. For some years he con- tinued these studies abroad and at home, and about 1825 became a student of medicine in London, where he studied at both St. Bar- tholomew's and Guy's. In connection with his numerous papers published in the Geological Journal (London) the author's name regu- larly appeared thus : "Abraham Gesner, M. D., F. G. S." He was also fellow or member of many other learned societies in both Amer- ica and Europe. Having practised for a time in Cornwallis, he removed to Parrsboro, and from the preface to his first published work, "Remarks on the Geology and Mineralogy of Nova Scotia," it is shown that in 1836 he was still there and practising. This book proved of great public service, both by bringing many of the reading people of Nova Scotia into touch with geological science, and by becoming the guide-book to the greatest geologist of the age, Sir Charles Lyell, who, in 1842, visited the province and made a "careful examination of some of the most difficult features of its geologic struc- tures." He had not only Gesner's book, but also the author himself as guide on part of that survey, and both proved of great assist- ance to him. Among Gesner's other and separately pub- lished works are the following : "Reports on the Geology of New Brunswick," Nos. 1, 2,
