BY JULIUS STIEGLITZ 



[Julius Stieglitz, Professor of Chemistry, University of Chicago, since 1905. A.M. 

 and Ph.D., University of Berlin, 1889; University Scholar, Clark University, 

 1890; Chemical Laboratory, Detroit, 1890-92; Decent in Chemistry, Univers- 

 ity of Chicago, 1892-93; Assistant, ibid. 1893-94; Instructor, ibid. 1894-97; 

 Assistant Professor, ibid. 1897-1902; Associate Professor, ibid. 1902-05.] 



THE very name of the branch of chemistry on whose relations to 

 other sciences I have the privilege of addressing you to-day tells 

 us with what sciences in particular, other than sister branches of 

 chemistry itself, organic chemistry must stand in closest relation- 

 ship. Since Wohler in 1828 by the synthesis of urea showed that 

 there is no fundamental difference between compounds prepared in 

 the laboratory and the same compounds formed in Irving organisms 

 under the influence of what until then was known as "vital force," 

 organic chemistry has become knitted more and more closely with 

 all branches of the great science of organic life. Its achievements in 

 the past culminated, we may say, in Fischer's synthesis of the impor- 

 tant hexoses and his magnificent development, with the aid of van ; t 

 Hoff and Le Bel's great theory, of the fact that there is an intimate 

 connection between the stereochemical configurations of organic 

 compounds and their production and assimilation in living organisms. 

 Great as these and similar achievements have been, they can be but 

 an earnest of what must still be done and is being done to have 

 organic chemistry do its full duty in the study of life's development, 

 its maintenance, its decay. The very fact that every stage of life 

 in the animal and the vegetable kingdom, in the lowest and the high- 

 est orders, is indissolubly connected with the formation or trans- 

 formation of very complex organic compounds shows us where the 

 path of the organic chemist must lead to, difficult as the way may 

 be. The plant physiologists, physiological chemists, physiologists, 

 anatomists, bacteriologists have piled up questions for us at a far 

 greater rate than we have been able to answer them. 



Before this host of questions there is one to which I wish to call 

 your attention in particular this afternoon in the time at our disposal, 

 and to whose answer I wish to bring a small contribution based on 

 work done with Messrs. Derby, McCrackon, and Schlesinger. The 

 composition, structure, and configuration of the innumerable com- 

 pounds connected with vital phenomena are problems of the highest 

 importance. But the questions as to how and why such molecules 

 are formed and transformed seem equally important, for if the trans- 



