1042 



EXPERIMENT STATION RECORD. 



(except pine straw) was still higher, clue, according to the author, to 

 the acid (tannin, etc.) they contain. Wood moss ranked with leaves 

 in absorptive power, and peat of good quality stood at the head of the 

 list. 



Analyses of commercial fertilizers, L. L. Van Slyke {New York 

 State Sta. Bui. 129, pp. 351-421). — Of the 735 samples, representing 500 

 different brands of commercial fertilizers collected during the spring 

 of 1897, 400 were complete fertilizers. The average composition of the 

 latter is shown in the following table: 



. I verage composition of complete fertilizers. 



Nitrogen 



Available phosphoric acid 



Insoluble phosphoric acid 



Potash 



Water-soluble nitrogen 



Water-soluble phosphoric acid. 



Percent guaranteed. 



Lowest. Highest. Average. 



0.40 

 1.93 



8.78 

 11.00 



2.09 

 7. 63 



Average 



per cent 

 found 

 above 

 guar- 

 antee. 



0.14 



.81 



"In 293 brands of complete fertilizers the amount of nitrogen found was equal to 

 or above the guaranteed amount, the excess varying from 0.01 to 2.73 per cent, and 

 averaging 0.30 per cent. In 107 brands the nitrogen was below the guaranteed 

 amount, the deficiency varying from 0.01 to 2.25 per cent and averaging 0.29 per 

 cent. In 87 cases the deliciency was less than 0.5 per cent. . . . 



"In 326 brands of complete fertilizers the amount of available phosphoric acid was 

 above the amount guaranteed, the excess varying from 0.01 to 10.08 per cent and 

 averaging 1.14 per cent. In 74 brands the available phosphoric acid was below the 

 guaranteed amount, the deliciency varying from 0.01 to 3.06 per cent and averaging 

 0.58 per cent. In 49 cases the deficiency was below 0.5 per cent. . . . 



"In 297 brands of complete fertilizers the amount of potash found was above the 

 guaranteed amount, the excess varying from 0.01 to 4.41 per cent and averaging0.53 

 per cent. In 103 brands the potash was below the guaranteed amount, the defi- 

 ciency varying from 0.01 to 8.32 per cent and averaging 0.47 per cent. In 85 of these 

 cases the deficiency was less than (1.5 per cent. In 88 cases among the 400 brands of 

 complete fertilizers the potash was contained in the form of sulphate free from an 

 excess of chloride. 



" The retail selling price of the complete fertilizers varied from $15 to $60 a ton and 

 averaged $28.92. The retail cost of the separate ingredients unmixed varied from 

 $1.80 to $34.25 and averaged $20.17, or $8.75 less than the selling price." 



Artificial fertilizers from apatite and similar mineral phos- 

 phates, G. E. Broms {TJgeshr. Landm., 42 {1897), No. 32, p. 421).— The 

 process of treatment consists in fusing the mineral phosphate with 

 sodium carbonate, when tetra calcium-sodium phosphate is formed. 

 This is insoluble in water, but easily soluble in ammonium-citrate solu- 

 tion. The reaction which takes place is as follows: 



9 OaO 3 P,,0;,+CaFL+3 Xa,C0 3 = 



W 2 Na!o } ,J P *°5+ 2 ^aFl+3 CO,. 



