THE WORK..OF EMI FISCHER AND 
HIS SCHOOL, ON, THE. CHEeMisak. 
OF THE “PROTEINS 
By R. H. ADERS PLIMMER, D.Sc. 
Assistant for Physiological Chemistry, University College, London 
THe PrRoxIMATE CONSTITUENTS 
Tue remarkable researches of Emil Fischer upon the chemistry 
of the proteins during the last few years, which are of no less 
magnitude than his classical work upon the Carbohydrates and 
the Purine Compounds, are of such great importance that it 
seems desirable to give a somewhat detailed account of these 
investigations and to indicate the methods by which Fischer 
has arrived at his results. 
Commencing with a minute study of the amino acids, which 
result in such variety as the products of hydrolysis of the 
proteins, Fischer next turned his attention to their separation 
as they result by hydrolysis, whereby a new method was 
perfected, which is now known as the ester method; and finally 
he has made extraordinary progress in the most important 
stage of synthesis. 
Fischer has lately published the results of his work from 
1899 to 1906 in book form, the opening pages of which consist 
of a lecture delivered to the Deutsche Chemische Gesellschaft 
in Berlin in January 1906. His researches are divided into 
three parts: 
I. The Amino Acids. 
If. The Hydrolysis of the Proteins. 
III. The Polypeptides. 
It has been known for many years from the work of Kihne, 
Neumeister, Chittenden, Schulze, Hlasiwetz, Habermann and 
others that the amino acids are the keystones of the protein 
molecule. It will make it easier to follow Fischer’s subsequent 
work if we here give a list of the amino acids which have been 
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