252 BOARD OF AGRICULTURE. 



compensations can be realized for it than the farmers can 

 afford to pay. 



Although our chances for the manufacture of ammonium 

 sulphate from the gas-house liquors and from the production 

 of animal charcoal have not yet been exhausted, it is plain that 

 the late cost of this article has reached a point where farmers 

 do well to look for more economical substitutes. The sulphate 

 of ammonia is a very efficient and also a very convenient form 

 of nitrogen for experimental purposes, when the cost of 

 material is still a matter of secondary consideration. Its 

 importance as a source of nitrogen for general farm purposes, 

 as far as quantity is concerned, has not materially changed 

 from the position it occupied more than twenty years ago, 

 when Von Liebig remarked, " Profitable farming will surely be 

 a failure in case its success depends on an adequate supply of 

 sulphate of ammonia." As soon as our farmers begin to ap- 

 preciate the importance of preparing the various kinds of 

 nitrogenous refuse material within their reach by a suitable 

 mode of composting during the autumn for a more immediate 

 action on the crops during the succeeding spring, there will be 

 much less need for paying for high-priced ammonia com- 

 pounds. By adopting more generally that course, large 

 quantities of active nitrogen compounds of an equally efficient 

 character may be secured, as a general rule, at more than 

 one-third less cost per pound of nitrogen ; for instance, from 

 blood, refuse, bones, and meat, from slaughter-houses and 

 glue-factories, animal waste matter of tanneries, fish, etc. 



Nitrate of Soda ( Chili saltpetre) . 



Nitric acid, 60.82 per cent. 



Sodium oxide, 35.68 " 



Calcium oxide, 0.13 " 



Magnesium oxide, 0.04 " 



Chorine 0.46 " 



Sulphuric acid, 0.08 



Insoluble matter (in water), 0.24 " 



Moisture, 2.00 " 



The sample was taken from the storehouse of a dealer in 

 Boston ; it contained 96.2 per cent, of nitrate of soda. The 

 standard strength prescribed by the Peruvian government is 



