VALUATION OF MANURES, 377 



also partly due to the fact, that we sometimes buy it as actual or 

 ready formed ammonia, and sometimes as potential ammonia ; that 

 is to say, we sometimes buy a nitrogeneous substance containing 

 no actual ammonia, but certain nitrogeneous compounds, which, 

 while decomposing in the soil, yield as much ammonia as the 

 nitrogen in tliem is capable of forming. The animal portion of 

 raw bone is such a substance, so are dried blood, horn, hair, hoof, 

 flesh and fish ; so ai-e woolen rags and refuse leather, but the lat- 

 ter decay so slowly that they possess less value as manure than 

 if they decomposed with greater rapidity. 



Formerly the cheapest source of supply was in Peruvian Guano 

 and the valuation of ammonia was obtained from its cost in that form. 

 Fifteen or twenty years ago it yielded from 16 to 19 per cent., but 

 latterly much less, while the price is 40 per cent, higher than then. 

 These considerations make a very wide difference in the price to 

 be set upon it. Besides, the Chincha Island furnishes a very 

 limited supply at present, and are nearly exhausted ; and what 

 is coming forward from Guanape is much inferior containing only 

 about 8 or 9 per cent, and the price $60 per ton (gold). Fifteen to 

 twenty years ago ammonia was estimated by some chemists as low 

 as 14 cts. and even 12| cts. per pound, now it appears that double 

 this price (in currency) falls short of wholesale rates. Even then 

 Dr. Stockhardt maintained that its value was not less than 25 

 cents, and says that, " although this price may appear high he be- 

 lieved it would bear a further addition rather than any reduction." 



At the present time we have a source of supply then unknown, 

 in fish guano ; but this as found in our markets is exceedingly 

 variable in quality )i sometimes containing not more than one or 

 two per cent, and from that up to seven or eight. Its quality, its 

 price and the supply are all so uncertain as to furnish at present 

 no satisfactory data by which to determine a standard of value. 



Sulphate of ammonia is another form in which it may be bought, 

 and which is largely employed in agriculture. The price of this 

 article has rapidly and largely advanced, in consequence of its 

 extensive employment for the growth of the beet root for sugar on 

 the continent of Europe. An inquiry lately addressed to a large 

 dealer in New York for the lowest price at which fifty tons could 

 be furnished for cash, brought an answer by which it appeared 

 that ammonia in this form commanded thirty cents per pound in 

 large quantities. 



In nitrate of soda we have a desirable form in which to supply 



