912 



ANNUAL REPORT OF THE 



Off. Doc. 



Two tendencies appear upon a comparison between these data and 

 the corresponding ligures for the spring of lOUl: A diminution of 

 soluble phosphoric acid and a general increase in the percentages of 

 reverted and insoluble phosphoric acid, while the total phosphoric 

 acid is slightly increased; this tendency appeared in a great many 

 brands. The use for acidnlation of rock phosphates which, though 

 richer in phosphoric acid, also contain more iron and alumina than 

 heretofore, would account for this tendency, since the phosphates in 

 acidulated goods from such rock tend to revert to insoluble forms. 

 The second tendency is toward the greater use of potash, which ap- 

 pears in both complete fertilizers and rock-and-potash goods. The 

 dissolved bones were very inferior. 



The cases of departure of goods from their guaranteed composition 

 observed this season, including only those cases in which it amounted 

 to tW'O-tenths per cent, or more, were as follows: 



Summary of Instances of Deficiency from Guaranty. 



c: 



9 



o 



b 



C 



Deficient In four constituents, 



Deficient in three constituents 



Deficient in two constituents 



Deficient in one constituent 



Total samples in which deficiency occurred, 



The cases of deficiency noted during the past seven seasons in 

 the goods as compared with their guaranties, expressed in per- 

 centage of the total number of goods of each class analyzed, are as 

 follows: 



