366 BOARD OF AGRICULTURE. 



VI. 



Prof. J. M. F. Wellmich's Chinese Plant-food. 



(Price, 50 cents per box of two pounds.) 



Total phosphoric acid, . . . .8.12 per cent. 



Sokible " .... 0.48 " 



Reduced " .... 1.72 " 



Insoluble *' . . . .5.92 " 



Nitrogen, 2.68 " 



Potassium oxide, . . . . .0.49 *' 



Gypsum, 52.84 *' 



Allowing $12 per ton for finely ground gypsum, this article 

 is worth per ton of 2,000 pounds, $35.44. 



It is sold in paper-boxes containing about two pounds each, 

 at 50 cents per box, making $500 per ton, including the 

 boxes. 



Crude Sulphate of Ammonia. 



The ammonia contained in this compound, is usually 

 obtained as a by-product iu the manufLicture of animal char- 

 coal from bones and other animal matter, and in the produc- 

 tion of illuminating gas from bituminous coal. The unpleasant 

 odor, which characterizes all the products resulting from these 

 operations, renders the ammonia, even after a careful separa- 

 tion, without entering into unusual expenses for refining, 

 unfit for other applications in the industrial arts. It suffices 

 for agricultural purposes to collect the ammonia in a moder- 

 ately diluted sulphuric acid ; to evaporate to dryness after the 

 acid has been neutralized, and to heat subsequently the resi- 

 due for the removal of the empyreumatic oils. An inferior 

 color and some odor do not affect its fitness for fertilizing 

 purposes. The ammonia obtained in both operations has 

 been formed during the destructive dry distillation of both 

 the bituminous coal and the animal matter. However, not 

 all the nitroofen contained in either kind of substance, is 

 changed into ammonia. Scarcely one-third of the nitrogen 

 contained in the coal, for instance, is transformed into that 

 compound. The remaining two-thirds combine with carbon 

 and sulphur, forming cj'an and sulpho-cyan. The degree of 



