44 



STUDIES OF AMERICAN BARLEYS AND MALTS. 



centage of phosphoric acid the less protein and the more starch. This 

 was true in over two-thirds of the samples examined. In this con- 

 nection Richardson a found that phosphoric acid fertilizers increased 

 the number of mealy grains, the effect being just the opposite to that 

 of nitrogen fertilizers, which increase the flinty characteristics. It 

 may thus be quite possible to decrease the protein content of barley 

 by the liberal use of phosphate fertilizers; in other words, since it is 

 fairly definitely known that nitrate fertilizers increase the protein 

 content of grains, phosphates may be used to increase the starch con- 

 tent, thus producing a low protein barley. Kunz, b however, could 

 find no relation between the amount of phosphoric acid and the ex- 

 tract yield. 



The amount of sulphur varies in the 84 samples of barley from 

 0.15 per cent to 0.256 per cent, with an average for all of the samples 

 of 0.182 per cent, following the protein content closely. As sulphur 

 is a natural constituent of protein, it might be expected that a high- 

 protein barley would contain more sulphur than one with low pro- 

 tein, and that this is the case was shown in over 80 per cent of the 

 samples. 



RELATION OF TOTAL TO SOLUBLE PROTEIN. 



Regarding the soluble protein, the results indicate that the greater 

 the total content of protein the smaller the percentage which is solu- 

 ble : in other words, a larger proportion of the total protein is soluble 

 in low-protein barleys than in high-protein barleys. The following 

 table will show how general this relation is when the barleys are 

 divided into groups according to their protein content : 



l>< tiff i a (lie ioldl mill IIic xolnblc jn'otrin content of Ixtrley. 



" U. S. Dept. Agr., Division of Chemistry, Bui. 9. 

 Uochenschr. Brau., 1906, 23: 530. 



