6 THE; PROTEINS OF THE WHEAT KERNEL. 



knowledge can be obtained. This review is interesting, also, as it shows the 

 slow development of the study of vegetable proteins and how the several 

 investigators have been influenced by the knowledge of the animal proteins 

 prevailing at the time the work was done. In carrying out his investiga- 

 tions of these proteins the writer has received the assistance of Messrs. 

 Voorhees, Campbell, Harris, and Clapp, for which he wishes here to make 

 acknowledgment ; but especially is he indebted to Prof. S. W. Johnson, 

 under whose direction and with whose advice and encouragement this work 

 was first undertaken in the laboratory of the Connecticut Agricultural 

 Experiment Station, where it has since been continued. 



REVIEW OF THE LITERATURE. 



The fact that gluten can be obtained from wheat flour by washing with 

 water appears to have been first published by Beccari. 1 



That alcohol extracts a protein substance from wheat flour was first stated 

 by Einhof, s who considered this to be the same as the gluten. 



Taddei 3 found that gluten consists of two substances, one of which is 

 soluble in alcohol, which he named " gliadin," the other insoluble in alcohol, 

 which he named ' ' zymom. ' ' 



De Saussure 4 obtained from wheat gluten about 72 per cent of plant- 

 albumin in the insoluble form, about 20 per cent of plant-gelatin, or, as he 

 proposed to call it, "glutin," and about i percent of mucin, which latter 

 substance he considered to be similar to the mucin described by Berzelius. 



Berzelius 5 thought that the alcoholic extract contained another protein 

 substance, which he called "mucin," and that the part of the gluten which 

 was insoluble in alcohol was so similar to albumin that he called this 

 ' ' plant-albumin. ' ' 



Boussingault 6 agreed with Einhof that the part of the gluten that was 

 soluble in alcohol was the same as the entire gluten protein. 



1 Beccari. Reference to this publication has, for many years, appeared in the literature 

 as Comon. Bonon. I. i, p. 122. It should be De Bononiensi Scientiarum et Artium Insti- 

 tute atque Academia Commentarii, 1745, ir, part i, p. 122. In this paper Beccari refers 

 to the fact that in 1728 he had orally communicated to the Academy the previously un- 

 published fact that wheat flour can be separated into two parts, one of vegetable, the 

 other of animal character. The substance of this communication was published in the 

 above-cited paper in which the separation of gluten from wheat flour, by washing with 

 water, is described. 



2 Einhof, Journal der Chemie von Gehlen, 1805, v, p. 131. 



3 Taddei, Annals of Philosophy, 1820, xv, p. 390. 



4 De Saussure, Schweiger's Journal, 1833, i,xix, p. 188. 



' Berzelius, Lehrbuch der Chimie, Auflage 3, 1837, vi, p. 453. 



6 Boussingault, Annales de Chimie et de Physique, 1838, ixv, p. 30. 



