260 BOARD OF AGRICULTURE. 



organic matter. It is of a very friable character. Its retail 

 price has been $25 per ton of 2,000 pounds in Boston. The 

 main agency for this and similar phospho-guanos is in Bal- 

 timore, Md. The sample was taken at Messrs. Bowker & 

 Co., Boston. 



I. — Brockville Mineral Phosphate. 



(Brockville Chemical and Superphosphate Works, Brockville, Ontario, Canada, A. 



Cowan, Manager. 



Phosphoric acid (insoluble), 35.21 per cent. 



Matter insoluble in hydrochloric acid, .... 6.46 " 

 Moisture, 2.50 " 



It consisted of the very fine pulverized phosphatic rock 

 apatite, which serves for the manufacture of superphosphates. 



II. — Brockville Superphosphate. 



(Mr. A. Cowan, Manager.) 



Total phosphoric acid, 21.30 per cent. 



Soluble phosphoric acid, 13.31 " 



Reduced " " 0.69 



Insoluble " " 7.30 



These two samples were kindly presented by Mr. A. Cowan ; 

 they were accompanied with a few specimens of apatite, as 

 found near Brockville. The superphosphate is a good article 

 of its kind ; it is offered for sale at the works, in small lots, at 

 $30 per ton of 2,000 pounds ; counting the soluble phosphoric 

 acid at 12.5 cents per pound, the article represents a market 

 value of from $33 to $34 per ton. The insoluble acid is here 

 of but little value, and ought not to enter into the valuation. 



Peruvian Guano. 



I.— (Messrs. Bagg & Batchelder of Springfield, Mass., March 27, 1876.— Old Lot.) 



Volatile and organic matter, 



Ash-constituents, 



Total phosphoric acid, 



Nitrogen (= ammonia 13.70), 



Potassium oxide, 



Sand, etc., 



Moisture (at 100° C), 



64.71 per cent. 



35.26 



14.52 



11.26 



1.89 



1.54 

 22.61 



