358 



tain 40 per cent, of silica, the reinaiuder beiug nearly all dolomite, or a 

 double carbonate of lime and magnesia. An examination of a sample 

 by Thomas C. Raymond, of Cambridgeport, Massachusetts, gave the 

 following result : 



Silica 30.3 



Protoxide of iron G.27 



Lime 20.6 



Magnesia 11.17 



Carbonic acid 32.11 



Total 100.45 



Several farmers of Grafton County state that by applications of this 

 fertilizer to corn, potatoes, turnips, fruit trees, &c., they have obtained 

 a more rapid growth and a very large increase in yield of crops. 



HOME-MADE FERTILIZEKS. 



A Virginia correspondent of the Department, after ex])ressing his ap- 

 preciation of the paper on " Bone Fertilizers," in our Monthly Eeport for 

 July, remarks that few farmers are sufficiently well informed in the prin- 

 ciples of chemistry to make a successful application of the waste material 

 on their farms. He adds, that this season he used fine charcoal, sawdust, 

 and Peruvian guano, with gypsum, for potatoes; and in another case 

 substituted wood ashes for the guano. The results were good in the 

 first case, l)ut were better still in the latter. The first-mentioned com- 

 post, with an addition of sulphate of soda, was used for cabbages with 

 good results, which would have been greatly enhanced if there had been 

 the requisite amount of moisture in the soil. 



FRAUD IX FERTILIZERS. 



B. Smith writes to the St. Louis (Missouri) Journal of Agriculture, 

 cautioning the public against a spurious fertilizer sold under the title of 

 "bat manure.'' He states that the genuine bat manure is about the 

 color of Scotch snuff, and that its weight is about the same as that of 

 bran, bushel for bushel, while the weight of certain materials of slight 

 fertilizing power, which have been vended under the title, is from four 

 to six times as great. In instances which liave con)c under his own in- 

 spection he judges the spurious fertilizer to be chietly composed of clay 

 procured from caves where it has become impregnated to some extent 

 with saltpeter. He has found the genuine bat manure a very effective 

 fertilizer. 



