516 ANNUAL REPORT OF THE Off. Doc. 



the drilling qualities of the goods. The fact that the phosphoric 

 acid in bone and rock are identical in character is probablj^ so 

 well known as to require no detailed consideration in this connec- 

 tion. 



The law having required the manufacturer to guarantee the amount 

 of -Certain valuable ingredients present in any brand he may put 

 upon the market, chemical analysis is employed to verify the guaran- 

 ties stamped upon the fertilizer sacks. It has, therefore, been deemed 

 desirable in this report to enter the guaranty filed by the manufac- 

 turer in the office of the Secretary of Agriculture, in such connection 

 with the analytical results that the two may be compared. An un- 

 fortunate practice has grown up among manufacturers of so word- 

 ing the guaranty that it seems to declare the presence in the goods of 

 an amount of valuable constituent ranging from a certain minimum 

 to a much higher maximum; thus, "Potash, 2 to 4 per cent." is a 

 guaranty not infrequently given. In reality, the sole guaranty is for 

 2 per cent. The guaranteed amounts given for each brand in the 

 following tables, are copied from the guaranties filed hj the maker 

 of the goods with the Secretary of Agriculture, tlie lowest figure 

 given for any constituent being considered to be the amount guar- 

 anteed. For compactness and because no essentially important fact 

 is suppressed thereby, the guaranties for soluble and reverted phos- 

 phoric acid have not been given separately, but are combined into a 

 single guaranty for available phosphoric acid ; in cases where the 

 maker's guaranty does not specifically mention available phosphoric 

 acid, the sum of the lowest figures given by him for soluble and re- 

 verted phosphoric acid is used. The law of 1879 allowed the maker 

 to express his guaranty for nitrogen either in terms of that element 

 or in terms of ammonia equivalent thereto; since ammonia is 

 composed of three parts of hydrogen and fourteen parts of nitrogen, 

 it is a very simple matter to calculate the amount of one, when the 

 amount of the other is given ; the amount of nitrogen multiplied by 

 1.214 will give the corresponding amount of ammonia, and the amount 

 of ammonia multiplied by 0.824 will give the corresponding amount 

 of nitrogen. In tliese tables, the expression is in terms of nitrogen. 

 The laws of 1901 and 1909 abolished the alternative and required 

 that the quantity shall be given in terms of nitrogen. 



Many manufacturers, after complying with the terms of the law, 

 insert additional items in their guaranties, often with the result of 

 rnisleading or confusing the buyer; the latter will do well to give 

 heed to those items only that are given as the law requires and that 

 are rcDresented in these tables: 



