No. 7. DEPARTMENT OF AGRICULTURE. 695 



MATEKIAL USED IN FEKTILIZERS 



The following observations on this head, were made respecting the 

 fertilizers analyzed in the Spring of 1910. They apply equally well 

 to those examined this Fall season. 



"The microscopic examination of the nitrogenous fertilizers for 

 leather, hair, and other materials the use of which without notice is 

 prohibited by the Act of May 1, 1909, revealed in no case such quan- 

 tity of any of these substances as might not fairly be regarded as an 

 accidental trace. No instance has been reported by the sampling 

 agents in which a declaration of the presence of such material has 

 been made. It is, however, a matter of quite general knowledge that 

 substances of this kind are being largely used in fertilizer mixtures ; 

 but, in most cases at least, only after such treatment as results in the 

 destruction of the characteristic tissues and, at the same time, wholly 

 or partly in that of the organic compounds originally present. The 

 Pennsylvania Agricultural Experiment Station is now conducting, 

 under the writer's supervision, an investigation to determine the 

 degree to which the acid treatment usually employed improves the 

 availability of the nitrogen in these substances. 



In conformity with the requirements of the Act of April 23, 1909, 

 many firms dropped from the brand names of goods manufactured 

 by them the word "bone" hitherto forming part of said names. Where 

 such change in name appears, it may be taken as evidence that the 

 phosphoric acid is derived, at least in part, from something else than 

 bone. In several cases where the word "bone" remains in the brand 

 name, the composition of the goods makes it clear that the law has 

 been violated. All such cases have been reported for legal action." 



