122 PROCEEDINGS OF THE ACADEMY OF [April, 



his college work. He took courses in Bacteriology, a science then 

 in its infancy, under Crookshank at King's College, London, and 

 under Klein at the College of State Medicine in the same city, 

 while he studied also under Pettenkofer at Munich, investigating 

 methods of sewage disposal, purification of drinking water and 

 other hygienic subjects. 



His duties at the University soon became irksome to him and he 

 longed for more opportunity for original research. He had in 

 1889 anticipated Koch in the discovery of the branched form of the 

 tubercle bacillus, and had conceived the possibility of the use of an 

 attenuated culture as a preventive of tuberculosis. In experiment 

 he had actually produced immunity in a Guinea-pig, and further 

 investigation of the problem was absorbing all his attention. 



As a result he withdrew from the University and determined to 

 establish a private laboratory elsewhere. Through the suggestion 

 of Dr. Henry C. Chapman he came to the Academy of Natural 

 Sciences. Dr. Dixon was elected a member of the Academy 

 February 25, 1890, and in the autumn of that year was granted 

 the use of a room at the eastern end of the old Race street building, 

 which he fitted up as a laboratory. Here for several years, personally 

 and through assistants, he carried on active bacteriological researches. 

 He took part in the meetings of the Academy, became a member of 

 the Microscopical and Biological Section and was elected Professor 

 of Microscopic Technology. He again visited Europe soon after 

 establishing his laboratory at the Academy and made the personal 

 acquaintance of Koch, Virchow and other noted foreign bacteriolo- 

 gists. 



Dr. Dixon's intimate association with the Academy naturally 

 led him to take a deep interest in the affairs of the institution and 

 at the close of the year 1891 he was elected a Curator, becoming 

 •executive Curator in 1893 and President on December 31, 1895, 

 retaining both offices until the time of his death. 



With the assumption of the duties of executive Curator his 

 personal researches in Bacteriology at the Academy, for the time 

 being, came to an end, and his whole time and energy were devoted 

 to the Academy's affairs and to the business management of a 

 large estate of which he was executor. 



At the time that his Curatorship began there had been little 

 change in the arrangement of the museum since the Academy had 

 first moved to its present site in 1876. There was but one salaried 

 man^in charge of the collections, and while several departments 



