664 THE POPULAR SCIENCE MONTHLY. 



me upon fulminating silver I was familiar with organic analysis, 

 and I very soon saw that all progress in organic chemistry de- 

 pended essentially upon its simplification ; for in this branch of 

 chemistry one has to do not with different elements which can he 

 recognized by their peculiar properties, but always with the same 

 elements whose relative proportions and arrangement determine 

 the properties of organic compounds. In organic chemistry an 

 analysis is necessary to do that for which a reaction suffices in 

 inorganic chemistry. The first years of my career in Giessen I 

 devoted almost exclusively to the improvement of the methods of 

 organic analysis, and the immediate result was that there began at 

 this little university an activity which had never before been seen. 

 For the solution of innumerable questions connected with 

 plants and animals, on their constituents, and on the reactions 

 accompanying their transformation in the organism, a kindly 

 fate brought together the most talented young men from all the 

 countries of Europe, and any one can imagine what an abundance 

 of facts and experiences I gained from so many thousands of 

 experiments and analyses, which were carried out every year, and 

 for so many years, by twenty and more indefatigable and skilled 

 young chemists. 



Actual teaching in the laboratory, of which practiced assist- 

 ants took charge, was only for the beginners ; the progress of my 

 special students depended on themselves. I gave the task and 

 supervised the carrying out of it ; as the radii of a circle have all 

 their common center. There was no actual instruction ; I received 

 from each individual every morning a report upon what he had 

 done on the previous day, as well as his views on what he was en- 

 gaged upon. I approved or made my criticisms. Every one was 

 obliged to follow his own course. In the association and constant 

 intercourse with each other, and by each participating in the work 

 of all, every one learned from the others. Twice a week, in winter, 

 I gave a sort of review of the most important questions of the 

 day ; it was mainly a report on my own and their work combined 

 with the researches of other chemists. 



We worked from break of day till nightfall. Dissipations and 

 amusements were not to be had at Giessen. The only complaint, 

 which was continually repeated, was that of the attendant (Aubel), 

 who could not get the workers out of the laboratory in the even- 

 ing, when he wanted to clean it. The remembrance of this so- 

 journ at Giessen awakened in most of my pupils, as I have fre- 

 quently heard, an agreeable sense of satisfaction for well-spent 

 time. 



I had the great good fortune, from the commencement of my 

 career at Giessen, to gain a friend of similar tastes and similar 

 aims, with whom, after so many years, I am still knit in the bonds 



