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SCIENCE 



[N. S. Vol. L. No. 12S5 



ticular interest is its combination with two 

 important classes of organic compounds 

 known as the aldehydes and ketones — a 

 discovery which found direct application 

 in the chemistry of the sugars. 



At the same time, Fischer, in collabora- 

 tion with his cousin, Otto Fischer, began 

 an investigation of the rosaniline dyestuffs 

 —the magenta of Perkin — ^which termi- 

 nated in the brilliant discovery that these 

 dyes were all derivatives of a hase tri- 

 phenylmethane. 



Fischer was made privat-docent in 1878 

 and at the end of the year was promoted 

 to the extraordinary professorship and 

 given entire cliarge of the analytical de- 

 partment in Baeyer's laboratory. 



Then began those classical investigations 

 into the active constituents of coffee and 

 tea, caffeine and theobromine, and their 

 relationship to xanthine and guanine — 

 decomposition products obtained from the 

 protein in the nucleus of cells — ^which ulti- 

 mately opened up an entirely new chapter 

 in plant and animal chemistry. 



In the Easter of 1882 Fischer accepted a 

 call as full professor (ordinarius) to 

 Erlangen, and three years later be ex- 

 changed this chair for one in Wiirzburg. 



After many weary trials, Fischer man- 

 aged to synthesize the most important 

 sugars — among them fruit and grape sugar 

 — and also to prepare many new ones arti- 

 ficially. It was in the course of this intri- 

 cate and laborious work that he had occa- 

 sion to put Van 't Hoff and Le Bel 's theory 

 of the asymmetric carbon atom to exhaus- 

 tive tests, with results which established the 

 theory more firmly than ever. 



It was also during these epoch-making 

 experiments on the sugars, when phenylhy- 

 drazine found constant application, that 

 Fischer hegan to suffer with chronic poison- 

 ing, due to the inhalation of the vapors of 

 this substance. Its effects he never got rid 



of, and from then on he was more or less of 

 a semi-invalid. This might perhaps explain 

 why in after years students found him 

 somewhat of a "grouch" and quite unap- 

 proachable. The testimony of some of his 

 students at "Wiirzburg seems to bear con- 

 clusive witness to the fact that in those 

 days, at least, he was not only an inspiring 

 leader and lecturer, but took a very active 

 interest in his research men. 



The appointment to a full professorship 

 made feasible his marriage to the lady he 

 had long courted, Frdiilein Agnes Gerlach. 

 The two made a striking pair. Both were 

 tall and handsome, with intellect and wit 

 aplenty. Their son has faithfully followed 

 in his father's footsteps. 



In 1892 came the crowning event of his 

 career. A. W. Hoffmann, who had been 

 professor at the Royal School of Chemistrj^ 

 in London for some years, and had there 

 taught such men as Crookes and Perkin, 

 and had later been appointed to the chair 

 of chemistry at Berlin University, died, 

 and Fischer was selected to succeed him. 



In Berlin Fischer continued his work on 

 the sugars. The fact that many of these 

 bring about fermentation led Fischer to 

 fruitful studies on the possible constitution 

 of ferments and their relationship to the 

 substances they act upon. 



Fischer's synthetic work in the sugar 

 series, particularly his studies into the con- 

 figuration of cane sugar, maltose and lac- 

 tose received a great impetus from the suc- 

 cess which attended his efforts in preparing 

 glucosides — combinations of glucose and one 

 or more other substances — artificially. By 

 the study of emulsin and other enzymes in 

 yeast on such glucosides, Fischer found 

 that the slightest change in the configura- 

 tion of the giucoside inhibited the action of 

 the enzyme. Zymase, another enzyme in 

 yeast, which is directly responsible for the 

 convei'sion of g'lucose into alcohol, behaved 



