6 THE VEGETABLE PROTEINS 



protein substances in seeds received immediate and extended recogni- 

 tion on the part of physiologists and of those familiar with proteins 

 of animal origin ; and as he claimed that the preparations which Ritt- 

 hausen had obtained by the aid of weak alkaline solutions were altered 

 products of the original protein constituents of the seeds, the work of 

 Ritthausen soon fell into disrepute and was discredited as not showing 

 the real protein constituents of the seeds which he had studied. Al- 

 though Ritthausen (415, 416, 417, 418, 421, 423, 425) soon after 

 showed that many of his preparations were largely or wholly soluble 

 in saline solutions and had for the most part retained their original 

 solubility unaltered, and also that the products obtained by direct ex- 

 traction of seeds with neutral salt solutions agreed in many cases 

 entirely with those which he had previously described, physiologists 

 continued to overlook and disregard his assertions. Since Ritthausen 

 ceased his work little has been done in this field outside of the work 

 carried on by the writer for the past eighteen years. During this time 

 papers have appeared which dealt with special questions in the chem- 

 istry of these substances, but no connected and extensive investigation 

 of the vegetable proteins has been undertaken by any one else. As 

 Ritthausen's researches were far from exhaustive, and left the subject 

 in such a state of confusion that it was impossible to form definite con- 

 clusions respecting much that he had described, the writer has directed 

 his attention largely to a review and extension of Ritthausen's work 

 with the hope of clearing up some of the existing uncertainties. For 

 these reasons the questions which are discussed in this monograph are 

 largely based on the writer's own work and are chiefly a review of sub- 

 jects which he has studied. 



