1918.] NATURAL SCIENCES OF PHILADELPHIA. 129 



ently had little shoots or branches. Dr. Dixon was very fond of 

 telling of the skepticism in the minds of the other students of this 

 laboratory, and perhaps even in the thought of open minded Klein 

 himself, when they were permitted to look at the branched forms in 

 this microscopic field. Some said the organisms were lying across 

 each other, or that the end of one bacillus projected against the 

 side of another; but Klein said, ''Dixon, if this branching is true, 

 you have made a great scientific discovery." He repeated his 

 work, he checked his technique, he wrote a splendid little paper 

 and illustrated it with a drawing which he made himself, showing 

 the new form. That little paper and that small illustration prepared 

 by the youth in research work attracted the attention of the 

 scientific world and fixed a reputation m science. 



This brilliant observation in all probability led him into further 

 research in tuberculosis, but in order to still better equip himself 

 as a teacher of hygiene, he did not return to his Chair without 

 having studied with the most noted hygienist of that time, Petten- 

 kofer of Munich. It was in 1889, while studying in the Laboratory 

 of Hygiene, Munich, so far as we know, that he undertook his 

 first studies in purifying large water supplies and the purification of 

 sewage. 



On his return to Philadelphia, late in 1889, he was made Professor 

 of Sanitary Engineering in the University of Pennsylvania, and in 

 October, 1889, we find him publishing a paper on the Treatment of 

 Sewage in London. An opportunity has not been had to review 

 the notes of his lectures given during this school year, but those 

 who had the privilege of listening to his instruction, and who are in 

 a position to contrast this instruction with the practices established 

 under his supervision in the State Department of Health of the 

 Commonwealth of Pennsylvania, see worked out in practical detail 

 what was then considered imaginative and by some medical men 

 almost impracticable and visionary. 



In 1890, Dr. Dixon gave up his association with the University 

 of Pennsylvania to become Professor of Bacteriology and Micro- 

 scopic Technology in the Academy of Natural Sciences of Phila- 

 delphia, going there solely in the capacity of a scientific worker. 

 Here he was stimulated by the great Leidy. 



During his last college teaching year — to be exact, the 19th of 



October, 1889 — the second event in the unusual career of this 



unusual man occurred. This date is an important one in the career 



of him to whom we pay tribute tonight. In the experimental 



9 



