26 THE CONNECTICUT AGEICULTUKAL 



whether the basis of the superphosphate is rock-phosphate or 

 bone, while if, as is generally the case, from one-third to one-half 

 or even more of the phosphoric acid in a superphosphate is insolu- 

 ble, it will make a very considerable difference in the agricultural 

 value of the article whether the insoluble portion consists of bone 

 or rock. In many cases it is not easy for the chemist to decide 

 with certainty what is the source of the phosphoric acid, and 

 there is therefore wisdom and economy in providing soluble phos- 

 phoric acid in these high grade goods. 



Plain Superphosphates. 



735. Superphosphate of Lime, 19 per cent. From stock of H. 

 J. Baker & Bro., N. Y. Sampled and sent by J. J. Webb, 

 Hamden. 



766. Acid Phosphate of Lime, 14 per cent, available phos- 

 phoric acid. H. J. Baker & Bro., N. Y., wholesale dealers. 

 Sampled from stock of Wilson & Burr, Middletown, by J. M. 

 Hubbard, Middletown. 



779. Dissolved Bone. Made by William L. Bradley, Boston. 

 Sold by H. D. Torrey, Putnam. Sampled and sent by W. L 

 Bartholomew, Putnam. 



135 T66 7T9 



Soluble phos. acid, 19.33 11.50 13.33 



Reverted phos. acid, 31 1.22 1.12 



Insoluble phos. acid, 35 .74 1.75 



Cost per ton, $34.50* $27.00 $40.00 



Cost of soluble phos. } $ 8.67f $10.40 $13.46 



acid per 100 lbs. f $8.92:]: $11.74 $15.00 



* In New York. 



, f Reckoning reverted and insoluble at 9 and 6 cents per pound respectively. 

 :}: Making no allowance for reverted and insoluble. 



735 contains a larger pei'centage of soluble phosphoric acid 

 than any sample previously brought to the Station. Superphos- 

 phates are made containing 35 per cent, and over, but these are 

 sold ^to manufacturers for vise in mixed fertilizers, and have not 

 found their way into our retail market. 



The cost of soluble phosphoric acid per 100 pounds, making no 

 allowance for the reverted and insoluble jihosphoric acid is, in 735, 



