46 STUDIES OF AMERICAN BARLEYS AND MALTS. 



the other hand, Evans finds that with 2-row barleys about 50 per 

 cent of the soluble protein is coagulable. which is a much larger 

 amount than that obtained in the work here reported on ordinary 

 0-row barleys. 



LECITHIN IN ITS RELATION TO PROTEIN AND PHOSPHORIC ACID. 



The amount of lecithin, or rather of alcohol-and-ether soluble 

 bodies, varies from 0.39 to 0.69 per cent, with an average of 0.53 per 

 cent, in accordance with the protein content. Stoklasa b found that 

 seed containing the most protein likewise held a higher percentage 

 of lecithin. This is substantiated by these data with but few excep- 

 tions; the amounts are, however, too small to make it possible to 

 d ra w many conclusions. 



There is no apparent connection between the amount of phosphoric 

 acid in barley and the lecithin content, probably due to the fact that 

 barley, like wheat, contains a larger proportion of a water-soluble 

 organic phosphorus compound, similar to, if not, phytin, and that 

 the amount of phosphorus found in barley is more nearly related to 

 this more abundantly occurring body than to lecithin, the latter 

 phosphorus compound being present in only relatively small quan- 

 tities. 



From the results given in Tables I and II it is seen that fully 35 

 per cent of the ash is composed of phosphoric acid compounds of 

 which less than 5 per cent is in the form of lecithin phosphoric 

 acid. The bulk of the phosphorus is present in the barley as a 

 calcium-magnesium-potassium salt of oxymethylene diphosphoric 

 acid, as was shown by Hart and Andrews/ who also showed that 

 practically no inorganic phosphorus compounds existed in grains. 

 The latter statement was afterwards corroborated by Schulze and 

 Castoro/ and more recently Windisch and Vogelsang e established 

 the same fact in regard to barley. There are several organic com- 

 pounds of phosphorus existing in plants, chief among which, besides 

 the previously mentioned compound, phytin, are the lecithin-like 

 bodies, which have a glycerin radicle, and the nucleins, which are pro- 

 tein compounds containing phosphorus. Phytin occurs in quite large 

 amounts, while the two latter compounds are present in smaller 

 quantities. 



Calcium, magnesium, and potassium, the more important ash con- 

 stituents besides phosphorus, form on an average about 2.7 per cent, 

 7.3 per cent, and 23 per cent, respectively, of the total ash. There 

 appears to be no appreciable difference in the amount of these con- 

 stituents in the ash of low-protein barleys and high-protein barleys. 



" J. hist. Brew.. T.-MMJ. 12: i_>0!. f New York Agr. Exp. Sta., Bui. 238. 



6 Ber. dent. chem. Ges., 1896, rf Zts. physiol. Chem., 1904, 41 : 477. 



_M): L'7i;i. c Wochenschr. Bran., 11)06. 23: 516. 



