No. 6. DEPARTMENT OF AGRICULTURE. 545 



name there is some disagi'eement between the manufacturer's statement filed 

 with the Department of Agriculture and the reports of sampling agents, or 

 with respect to which the information is incomplete in some other important 

 particulars. It is deemed best not to delay the publication of this bulletin until 

 the information upon the points in question has been secured, but it is ex- 

 pected that the facts will have been ascertained with sufficient exactness to 

 warrant the publication of these analyses in the fall bulletin 



FERTILIZER ANALYSES AUGUST 1, TO DECJEMBER 31, 19UT. 



Since August 1, 1906, there have been received from authorized sampling 

 agents eleven hundred and ten fertilizer samples, of which four hundred and 

 twenty-two were subjected to analysis, the remainder being rejected either 

 because they represented brands analyzed last season or because they were re- 

 garded as not certainly representative of the brand whose name they bore. 

 When two or more samples representing the same brand were received equal 

 • portions from the several samples were united and the composite samples were 

 subjected to analysis. 



The samples analyzed group themselves as follows, 266 complete fertilizers, 

 furnishing phosphoric acid, potash and nitrogen; 7 dissolved bones, furnishing 

 phosphoric acid and nitrogen; 71 rock-and-potash fertilizers, furnishing phos- 

 phoric acid and potash; 43 acidulated rock phosphates, furnishing phosphoric 

 acid only; 34 ground bones, furnishing phosphoric acid and nitrogen, and one 

 miscellaneous sample, which group includes substances not properly classified 

 under the foregoing heads. 



The determinations to which a complete fertilizer is subjected are as follows: 

 (1) Moisture, useful for the comparison of analyses, for indication of di'y con- 

 dition and fitness for drilling, and also of the conditions under which the fertili- 

 zer was kept in the warehouse. (2) Phorphoric acid — total, that portion soluble 

 in water, and of the residue, that portion not soluble in warm ammonia citrate 

 solution (a solution supposed to represent the action of plant roots upon the 

 fertilizer), which is assumed to have little immediate food value. By difference, 

 it is easy to compute the so-called "reverted" acid, which is the portion insolu- 

 ble in water, but soluble in the citrate. The sum of the soluble and reverted is 

 commonly called the "available" phorphoric acid. (3) Potash soluble in water — 

 most of that present in green sariH marl and crushed minerals, and even some 

 of that present in vegetable materials such as cotton-seed meal, not being in- 

 cluded because insoluble in water even after long boiling. (4) Nitrogen — This 

 element is determined by a method which simply accounts for all present, with- 

 out distinguishing between the quantities present in the several forms of am- 

 monium salts, nitrates or organic matter. (5) Chlorin; this determination is 

 made to afford a basis for estimating the proportion of the potash that is pres- 

 ent as chlorid or muriate, the cheaper source. The computation is made on the 

 assumption that the chlorin present, unless in excess, has been introduced in 

 the form of muriate of potash; but doubtless there are occasional exceptions 

 to this rule. One part of chlorin combines with 1.326 parts of potash to form 

 the pure muriate; knowing the chlorin, it is, therefore, easy to compute the 

 potash equivalent thereto. (7) In the case of ground bone, the state of sub-di- 

 vision is determined by sifting through accurately made sieves; the cost of 

 preparation and especially the promptness of action of bone in the soil de- 

 pends very largely on the fineness of its particles the finer being much more 

 quickly useful to the plant. 



The law having required the manufacturer to guarantee the amount of cer- 

 tain valuable ingredients present in any brand he may put upon the market, 

 chemical analysis is employed to verify the guaranties stamped upon the ferti- 

 lizer sacks. It has, therefore, been deemed desirable in this report to enter the 

 guaranty filed by the manufacturer in the oflice of the Secretary of Agricul- 

 ture, in such connection with the analytical results that the two may be com- 

 pared. An unfortunate practice has grown up among manufacturers of so 

 wording the guaranty that it seems to declare the presence in the goods of an 

 amount of a valuable constituent ranging from a certain minimum to a much 

 higher maximum; thus, "Potash, 2 to 4 per cent." is a guaranty not infre- 

 quently 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 guar- 

 anties filed by the maker of the goods with the Secretary of Agriculture, the 

 lowest figure given for any constituent being considered to be the amount 

 guaranteed. For compactness and because no essentially important fact is 

 suppressed thereby, the guaranties for soluble and reverted phosphoric 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 spe- 

 cifically mention available phosphoric acid, the sum of the lowest figures given 



35—6—1907. 



