18 BULLETIN 158, U. S. DEPARTMENT OF AGRICULTURE. 



arrived at from the results obtained with the Van Slyke method. 

 The Millon reaction and the Hop kins -Cole reaction were both nega- 

 tive, showing the absence from this prote inlik e compound of the 

 tyrosine and the tryptophane radicles. 



A very large number of compounds intermediary between the pro- 

 tein and its primary hydrolysis products may occur, depending on a 

 great variety of conditions so that the actual identification of the com- 

 pound under discussion would be a difficult matter. However, the 

 nature of this compound may be approximately determined by the 

 results obtained in the study of the two extracts by the Van Slyke 

 method. These results have been already discussed and they indi- 

 cate the presence in the base goods of a compound of a proteose na- 

 ture, which because it gives a biuret test, must be composed of at 

 least three amino acids. The results indicate still further that the 

 compound is composed of acid amide radicals, diamino acids, particu- 

 larly lysine, and mo no ami no acids, those containing amino nitrogen 

 and especially those containing non-amino nitrogen. Since the fig- 

 ures obtained by the nitrogen partition method are subject to a cer- 

 tain amount of error when applied to such a mixture the figures can 

 only be taken as apj^roximate for the various forms of nitrogen which 

 make up this compound. 



The figures given for arginine in the table are probably only influ- 

 enced by any cystine present. Attempts to isolate cystine from the 

 base goods failed, although it seems unlikely that this compound can 

 be absent. The figures for histidine and lysine are undoubtedly too 

 high, since they include all of the other nitrogenous compounds pre- 

 cipitated by phosphotungstic acid, so that the absolute amount of 

 these compounds in base goods can not be correctly determined by 

 this method. The figure given for the amount of amino nitrogen 

 present as mono amino acids may be a little high, while the non- 

 amino nitrogen figure is open to considerable error. 



In Table A 7 ! are given the primary hydrolysis products of a number 

 of proteins which may be present in the base goods. These results 

 were obtained by the esterification method and show how the differ- 

 ent proteins vary in the nature and amount of the units composing 

 them. Many mono amino acids, besides leucine and tyrosine, occur 

 in these proteins, and there must consequently be present in the base 

 goods amino acids other than the two isolated. This is apparent 

 from the composition of the various proteins shown in the table. 

 Owing to the large amount of amide nitrogen present in the f ertilizer, 

 which was split off by the acidulation of the original proteins of the 

 trade wastes, it may be concluded that considerable quantities of 

 aspartic or glutamic acids are present in this sample of base goods. 



The conclusions which are to be drawn from the results obtained 

 by the examination of this fertilizer by means of the analytical and 



