SUPERPHOSPHATE OF LIME 285 



manures are mixed with the soil is represented in the last 

 line nearly 22 per cent in M -'s, and 12.3 per cent in 

 D - 's. It should be observed that the total amount of phos- 

 phate is very nearly alike in M 's and D 's. This is 



obtained by adding the insoluble phosphate to the precipitated 



phosphate. D 's is therefore equal to M 's in final 



effect, so far as phosphates are concerned, yet it is quite 

 inferior in immediate value, and should be afforded at a less 

 price, or else more carefully made, so as to raise the amount 

 of superphosphate. 



D -'s compares well with English average specimens of 

 No. 4. 



These are both valuable manures, and undoubtedly M 's 



is cheap enough at the present price, $50 per ton, if its quality 

 is maintained as good as my analysis represents. Still we may 

 hope that as good an article may be purchased, before many 

 years, at a much less price. This can not be expected until 

 the consumption is greatly increased, and more competition 

 arises among manufacturers. 



It is proper to state that I have no connection with the 

 parties concerned in the manufacture or sale of these manures ; 

 and receive no compensation for the months' labor expended 

 upon the analyses, except the satisfaction of contributing to 

 the advantage of purchasers. 



It should be borne in mind that the value of these manures 

 may be found to vary greatly at different times, and the 

 farmer can only be fully protected from unprofitable expendi- 

 ture, by the frequent publication of analyses made upon 

 different samples. 



