THE NITROGEN OF PROCESSED FERTILIZERS. 



15 



facture of the base goods the proteins contained therein have been 

 changed. This change is shown to be a deep-seated one, since five of 

 the compounds which are known to be final products of protein 

 hydrolysis by acids are found. This, however, can not be taken to 

 mean that the proteins have been completely hydrolysed by the acid 

 treatment since it is possible to have present in the product of partial 

 hydrolysis of proteins not only the diamino and monoamino acids, 

 but also such intermediate compounds as polypeptids, peptones, 

 proteoses, etc. 



In this connection the results obtained by use of the Van Slyke 

 method, which are given in Table V, are of particular interest. As 

 has been already stated, the base goods were extracted (1) with boil- 

 ing water and (2) with boiling acid. In the former case only slight 

 further hydrolysis of the materials in the base goods is to be expected 

 since the free acid in the fertilizer is extremely weak, and the boiling 

 temperature, 100° C, is that which was reached in the process of 

 manufacture. In the case of the second extract complete hydrolysis 

 of all the proteins or proteinlike materials is certainly to be expected, 

 since in addition to the original hydrolysis the material was boiled 

 with strong hydrochloric acid for 24 hours, which treatment in the 

 case of most proteins is sufficient for complete hydrolysis. The dif- 

 ferences in the results obtained from the analyses of the two extracts 

 may, therefore, be expected to throw some light on the question of 

 the completeness of hydrolysis of the original proteins by the acid 

 processing. 



Table V. — Nitrogen forms as determined by the Van Slyke method. 



Form of nitrogen. 



Results expressed in per 

 cent of base goods. 



Results expressed in per 

 cent of total N in base 

 goods. 



„ 



H 2 extract. 



HC1 extract. 



H 2 extract. 



HC1 extract. 



TotalN 



1.610 



1 1. 372 



1.238 



.374 



.031 



.111 

 .117 



.081 



.543 

 .114 



1.610 



1.435 



1.175 



.382 



.074 



.104 

 .070 

 .117 



.546 

 .133 







Total soluble N 



185.24 



1 14. 76 



23.23 



1.95 



6.89 

 7.26 

 5.06 



33.75 

 7.10 



88.64 





ill. 36 





23.70 





4.61 



Diamino acid fraction: 



6.46 





4.38 





7.26 



Monoamino acid fraction: 



33.92 





8.27 







i Obtained indirectly. 



First it will be noticed that total soluble nitrogen in the hydro- 

 chloric acid extract is 88.64 per cent of the total N, while that of the 

 water extract is 85.24 per cent, showing a difference of 3.4 per cent 

 soluble N produced by further hydrolysis of the materials in the 

 base goods. Correspondingly there is a decrease of insoluble N. 



