DEMOCRATS AND ARISTOCRATS IN SCIENTIFIC RESEARCH 417 



sugar for the people. What Fischer was interested in was the composi- 

 tion, the structure of sugars, and to few men has it been given to pene- 

 trate the subject so deeply. Molecules of the sugars, like those of all 

 substances, are composed of atoms which stand to each other in definite 

 relations in space. The molecules, that is to say, the essential units 

 of a certain group of sugars, all contain six atoms of carbon, twelve of 

 hydrogen and six of oxygen, and yet the group includes several distinct 

 substances because the arrangement of these atoms in space is different. 

 For instance, one possible difference in arrangement is that in which 

 the atoms of two molecules are so disposed that the three dimensional 

 molecule of one is the mirror image of the other. When the likeness is 

 so close the properties are identical, except for one feature. A ray of 

 light which has been "polarized" by passing through a Nicol prism is 

 bent to the right by one form, by the other to the left. With greater 

 variation in the arrangement greater differences in chemical properties 

 are noted. Abstruse matter this, and all theory, for no piling up of 

 lenses has ever been sufficient to enable man to gain a faint glimpse of 

 one of these hypothetical molecules. Yet the theory stands, and by 

 virtue of the enormous number of predictions made upon its basis which 

 were later realized by experiment. And to Fischer, using the sugars, 

 is due much of the credit for the establishment of this, the so called 

 Van't Hoff and LeBel hypothesis. 



The study of sugars led him to the substances that in nature act 

 upon them, the enzymes or ferments, substances like the diastase which 

 acts upon starch converting it into glucose. That enzymes are specific 

 in their action had long been known, but it remained for Fischer to 

 demonstrate how high that degree of specificity is. To one of a pair of 

 extremely closely related substances, differing only in a slight variation 

 in the arrangement of their atoms in space, a given enzyme is neutral, 

 while acting readily upon the other. A slight change in the latter 

 renders it, too, insusceptible. The proof of this led Fischer to the 

 conclusion that enzymes act upon their substrates through exact spacial 

 approximations, his famous key and lock analogy. 



So much to show the nature of Fischer's work, to indicate the type 

 of mind of the man. It was by no means the only, or even the largest, 

 problem this brilliant and versatile chemist undertook. In another 

 class of compounds, the proteins, was a chaos which seemed of incon- 

 ceivable complexity until Fischer pointed the way through. Proteins 

 are peculiarly biological; without them there would be no life, and 

 differences in protein are probably ultimately responsible for differ- 

 ences in living forms, inasmuch as protein must carry the hereditary 

 characteristics. They are found in greatest bulk in the animal kingdom, 

 though not confined to it, and include such well known substances as 

 egg white, the casein of milk, and flesh of all forms. In the analysis 



VOL. XIL— 27. 



