AGRICULTURAL CHEMISTRY. 1103 



suitable conditions a very considerable degree of accuracy can be obtained in 

 deterniining ammonia, histidin. argiiiin. and lysin. We also believe that these 

 determinations atford the best means now available for differentiating the 

 many forms of proteins. . . . The data obtained respecting the determination of 

 ammonia make it highly probable that the results are very accurate, and that 

 this ammonia originates from an amid union in the protein molecule." 



Determinations of the actual quantities of histidin, arginin. and lysin present 

 in a number of proteids have shown that the amount of nitrogen contained in 

 these bases corresponds closely with that precipitated by phosphotungstic acid. 



" In view of the close agreement between the amount of nitrogen precipitated 

 by phosphotungstic acid and the sum of the nitrogen contained in the arginin, 

 histidin. and lysin which the large number of different proteins from many 

 sources yield on hydrolysis, it seems improbable that other basic products than 

 those just named will be found in the future among the decomposition products 

 of the proteins. In respect to accuracy, the determinations of histidin, arginin, 

 and lysin appear to leave little to be desired if the methods of analysis are 

 carefully and properly carried out. 



" It was found that for many proteins a much longer hydrolysis was neces- 

 sary to liberate all of the bases than has been heretofore supposed. Apparently 

 a considerable part of these bases is present in some of the proteins in very 

 difficultly hydrolyzable combinations which require 24 hours, or more, con- 

 tinued boiling with 25 per cent sulphuric acid for their complete dissolution. 

 This condition was found to hold especially for the proteins of leguminous 

 seeds. 



" The wide differences between seed proteins in the proportion of nitrogen 

 precipitated by phosphotungstic acid is chiefly caused by differences in the 

 amount of arginin which was obtained from all of them. This forms about 1 

 per cent of the protein containing the least, and over 14 per cent of those con- 

 taining the most, basic nitrogen. The amount of histidin which was also 

 obtained from all of the proteins was nearly the same in the majority of the 

 proteins analyzed, that is, about 2.5 per cent. The amounts of lysin found in 

 the several proteins differed considerably, none being present in any of the 

 alcohol soluble proteins, 4 to 5 per cent in most of the leguminous seed proteins, 

 and over 6 per cent in conalbumen from hen's egg. 



" The proteins, when arranged in the order of their yield of arginin, fall 

 into three groups : first the oil seeds, then the leguminous seeds, and finally the 

 cereal grains — the only exception being the glutelin of maize, which is one of 

 the least well characterized and studied of all the proteins in the list, and may 

 be a mixture of several different proteins. . . . 



" We have in the chemical constitution of these seed proteins an apparent 

 relationship not only to the biological relations of the plants which produced 

 them, but also to the chemical constitution of the seeds themselves." 



Products formed by the decomposition of casein, I. W. Bissegoer and L. 

 Stkc.manx {/Jnclir. J'In/.siol. Cliciii., .IcS (IDOS), Xo. 2, pp. I.'i7-J52 ; ahs. in Jour. 

 Clicni. Soc. [London], 96 {1909), No. 555, I, p. 72). — Details are given for the 

 isolation of a new basic substance obtained from the lysin fraction. When 

 casein is digested with pancreatin and pepsin in the presence of toluene and 

 sodium fluorld, fotra- and ponta-methylenediamins can not be isolated. 



On the presence of isoleucin in casein, R. Weitzen3()('k (Monatsh. Chem., 

 27 (1906), pp. 831-S.i7; ah.s. in Milchir. Zrnthl., 5 (1909), No. 1, p. J8).— Among 

 the cleavage products in the hydrolysis of casein, the author found leucin, 

 isoleucin, and phenylalanin in the first fraction when precipitated with phos- 

 photungstic acid. These substances were not obtained in the pure state but 

 were always united with amiuovaleric acid. 



