Dixon, Samuel Gibson, M. D., LL. D., Bryn Mawr, Pa., was born of Quaker parentage in the city of Philadelphia in the family homestead below Bartram’s Botanical Gardens, March 23, 1851. His early education was received at the Friends’ Schools in that city and was supplemented by private tutors, by whom he was prepared for Harvard College. His health failing, however, he went abroad for recreation and study. Returning home he set himself to acquire a thorough knowledge of business principles, taking a course at the Mercantile College. On the conclusion of this he studied conveyancing under the late Edward Bedlock of Philadelphia. He then studied law in the office of his brother, Edwin Saunders Dixon, Esq., attended the law course of the University of Pennsylvania, and was admitted to practice at the bar of Philadelphia June 30, 1877, continuing in the active practice of that profession for ten years. The practice of law left him with trusteeships of importance which have necessarily kept him well to the front in affairs. Under the stress of desk and office work his health again failed, and his tastes inclining him to make a hobby of scientific medicine he matriculated in the Medical Department of the University of Pennsylvania, in Philadelphia, from which he was graduated with honor in 1886. While still an undergraduate, however, he received the unusual compliment of an appointment by the trustees to the position of Assistant Demonstrator of Physiology. During his last year in the medical school he suffered from a serious attack of typhoid fever, which made a foreign trip again desirable in the opinion of his physicians. Being greatly interested in the infant science of bacteriology, as soon as his strength permitted, he entered the Bacteriological Department of King’s College, London, from which he was graduated. He also took a course in the College of State Medicine, London, under Professor Klein, and it was while prosecuting observations under that master in bacteriology that he made the discovery of branched forms of tubercle bacilli hitherto unnoticed. He also studied under Pottenkofer, in Munich, and made a careful study of the methods of filtration of water and disposition of sewage then in vogue in the capitals of Great Britain and Europe. Returning to Philadelphia in 1888, his alma mater recognized the value of his attainments by appointing him the first Professor of Hygiene in the newly created chair in the Medical Department, and also Dean of the Auxiliary Department of Medicine. While in this position he embraced the opportunity to establish the first Laboratory of Hygiene in the University. Two years later he resigned these positions to accept the appointment of Professor of Bacteriology and Microscopical Technology at the Academy of Natural Sciences of Philadelphia, of which institution he became Executive Curator in 1892 and President in 1896. During this period his mind reverted constantly to the problem of the branched tubercle bacillus and the possibility which he had conceived of obtaining immunity to that disease by the introduction into the human economy of attenuated bacilli or of fluid extracts from the same, and he prosecuted original researches on this subject untiringly. On October 19, 1889, he published in the Medical News of Philadelphia the results which he had then reached in producing immunity to that disease in the lower animals, and has constantly kept the profession informed of his investigations by means of addresses and contributions to medical and scientific journals. The two theses or propositions on which he based this theory of possible immunity to the tubercle bacillus are as follows: “First. It is possible that by a thorough filtering out of bacilli from tubercular material a filtrate might be obtained and attenuated so that by systematic inoculations a change might be produced in living animal tissues that would enable them to resist virulent tubercle bacilli. Second. To bring about a chemical or physical change in living tissues that would resist tubercular phthisis it is possible that inoculations with the bacillus would have to be made; yet, before this could be done, the power of the virulent bacilli would have to be diminished; otherwise the result would be most disastrous.” In the autumn of 1890, Doctor Dixon, inspired by the announcement of Professor Koch that he had succeeded in developing a substance which possessed the power of preventing the growth of the tubercle bacillus in the human economy, again visited Europe in order to assure himself of the accuracy of the reports and in the interest of humanity as well as of the various scientific and medical institutions with which he was connected, and had interviews with Koch, Virchow and Dubois Raymond. That Doctor Dixon has always recognized the claims of the community as a whole on members of his profession is sufficiently proven by the fact that he is officially connected with so large a number of scientific, philanthropic and educational institutions. He has been for eighteen years Executive Curator of the Philadelphia Academy of the Natural Sciences, and for fourteen years its President. For a number of years he was a member of the Board of Education of the city of Philadelphia an as Chairman of the Committee on Hygiene devoted much time to improving the sanitary condition of the schools. He is an officer of the Ludwick Institute, the Society for the Prevention of Tuberculosis in Pennsylvania, the Zoological Society of Philadelphia and the Grandom Institution, a member of the Council of the American Philosophical Society and of the Historical Society of Pennsylvania, a director of the Wistar Institute of Anatomy of the University of Pennsylvania, a Fellow of the College of Physicians of Philadelphia, a member of the American Medical Association, the Medical Society of the State of Pennsylvania, the Philadelphia County Medical Society, the American Association for the Advancement of Science and the American Archeological and Asiatic Society, and one of the originators of the Geographical Society of Philadelphia. An enthusiast on field sports from his early boyhood, many of his vacations have been spent in salmon and trout fishing and the hunting of big game. He has been an enthusiastic and successful breeder of choice cattle and sporting dogs. He is a member of the American Kennel Club, of which he was the first Secretary, and President of the Philadelphia Kennel Club. Among the social clubs of the country he is a member of the Philadelphia Club, the Merion Cricket Club, the University Club, the Tarrantine Golf Club and the Radnor Hunt.
Dolan, James A., 346 Broadway, New York City.
Dolan, Thomas E., M. D., 250 Elizabeth Avenue, Elizabeth, N. J.
Donahue, Dan A., 178 Essex Street, Salem, Mass.; outfitter to men and women.
Donahue, R. J., cashier of the National Bank of Ogdensburg, N. Y.
Donnelly, Hon. Thomas F., a justice of the New York City Court, 257 Broadway, New York City.
Donoghue, D. F., M. D., 240 Maple Street, Holyoke, Mass.
Donovan, Daniel, 21 High Rock Street, Lynn, Mass.; an authority on heraldry, armorial bearings, etc.; particularly as the same relate to Ireland.
Donovan, Colonel Henry F., editor and proprietor of The Chicago Eagle, No. 504 Teutonic Building, Chicago, Ill.; was commissioned as Colonel by the Governor of Illinois, and served that State four years as Inspector-General of the Illinois National Guard.
Donovan, John W., real estate, mortgages and insurance, 360 West One Hundred Twenty-fifth Street, New York City.