VI. KEPOET OF ANALYSES OF COMMERCIAL FER- 

 TILIZERS FOR THE SPRING OF 1896.* 



SUMMARY. 



During the spring of 1896, there were collected 423 samples 

 of commercial fertilizers, representing 313 different brands. 



Of these 303 different brands, 273 contained nitrogen A'-arying 

 in amount from 0.78 to 15.59 per cent. The average of all the 

 guarantee-analyses was 2.58 per cent of nitrogen, while the aver- 

 age amount found by the Station analysis was 2.86 per cent. 



There were 301 brands which contained available phosphoric 

 acid, varying in amount from 0.65 to 16.88 per cent. The aver- 

 age amount of available phosphoric acid found by Station analy- 

 sis exceeded the average guarantee-analysis by 0.39 per cent, 

 the average of all the guarantee-analyses being 7.89 per cent and 

 the average actually found being 8.28 per cent. 



There were 276 brands which contained potash, varying from 

 0.11 to 50.34 per cent. The average amount of potash found 

 by our analysis exceeded the average guarantee-analysis by 

 0.33 per cent, the average of all the guarantee-analyses being 

 4.76 per cent, and the average actually found being 5.09 per cent. 

 Of the 313 different brands collected, 139 were below the manu- 

 facturer's guarantee-analysis in one or more constituents, in 

 amounts varying from 0.03 to 4.41 per cent. 



The amount of nitrogen was below the guarantee-analysis of 

 the manufacturer in 40 brands, the deficiency varying from 0.03 

 to 0.93 per cent and averaging 0.28 per cent. In 20 of the 40 

 brands, the deficiency was not greater than 0.25 per cent; in 14 

 brands it was over 0.25 and below 0.50 per cent; in 6 brands it 

 was over 0.50 and below 1 per cent. 



The amount of phosphoric acid was below the manufacturer's 

 guarantee-analysis in 84 brands, the deficiency varying from 0.04 

 to 4.41 per cent and averaging 0.77 per cent. In 26 of the 84 

 brands the deficiency was less than 0.25 per cent; in 13 cases it 

 was above 0.25 and below 0.50 per cent; in 26 brands it was 

 above 0.50 and below 1 per cent; in 13 brands the deficiency was 



♦ Published aUo as Bulletin 107. 



