SUPERPHOSPHATE OF LIME. 267 



supplant guano itself, nitrates added to superphosphate may 

 be expected to produce all the good effects resulting from 

 the mixture of guano and superphosphate. 



The following compound is therefore recommended with 

 confidence. The amount of nitrogen in the nitrate here 

 used, is about the same as that in the best mixtures of 

 guano, salts of ammonia, and superphosphate of lime. 



40 lbs. crude superphosphate, 2 cts., . . $0.80 



10 " soda ash, 3 cts., 30 



50 " nitrate of potash, or saltpetre, 6| cts., 3.25 



100 « cost $4.35 



OR, 



38 lbs. superphosphate, 2 cts., . . . |0.76 



9 " soda ash, 3 cts., 0.27 



43 " nitrate of soda, (Chili saltpetre,) 5^ cts., 2.36 



100 « cost $3.39 



The cost of these per pound is greatel* than that of the 

 mixtures before proposed, and above that of the commercial 

 mixture. Still, it is believed that the mixture of nitrates 

 with superphosphate, even at the above rates, will be found 

 an economical manure, especially when one prepares for 

 himself small quantities of superphosphate from such bones 

 as may be collected in his neighborhood, and where guauo is 

 not to be had. 



No cheaper or better addition can be made, in the small 

 way, by the farmer, than the droppings of the hen-roost and 

 poultry yard, home-made guano. 



About equal parts of superphosphate, sprinkled with a 

 little ashes, and of fowl droppings, may be recommended 

 for trial. 



