SOLUBLE PHOSPHATES IN FARM-YAUD MANURE. 



73 



" He did say so," 1 irplit'd, " aud it may be true, but the above 

 figures do not seem to prove it. Wlien he wrote tlie sentence you 

 have quoted, be probably bad reference to the fact that he found 

 more soluble phosphate of lime in rotted manure than in fresh 

 manure. Thus, he found in 5 tons of fresh and 5 tons of rotted 

 manure, the following ingredients : 



5 TONS, 

 (10,000 LBS.) 



Fresh manure.. 

 Rotted manure. 





29.!) 

 38.~ 



:38.6 

 57 3 



iSol. Insol. 



68.5 

 95.5 



57.3 

 44. ti 



9.9 



4.5 



5.59 

 805 



" It will be seen from the above figures that rotted manure con- 

 tains more soluble pJiosphiie of lime tJi in fresh manure. 



" But it does not follow from this fact that any of the insoluble 

 phosphates in fresh manure have been rendered soluble during the 

 fermentation of the manure. 



" There are more insoluble phosphates in the rotted manure than 

 in the fresh, but we do not conclude from this fact that any of 

 the phosphates have been rendered insoluble during the process of 

 fermentation — neither are we warranted in concluding that any of 

 them have been rendered soluble, simply because we find more 

 soluble phosphates in the rotted manure." 



" Very true,' said the Doctor, " but it has been shown that in 

 tlie heap of manure, during fermentation, there was an actual in- 

 crease of soluble mineral matter during the first six months, and, 

 to say the least, it is hi7:hly probable that some of this increase of 

 soluble mineral matter contui led more or less soluble phosphates, 

 and perhaps Dr. Voelcker had some facts to show that such was 

 the case, although he may not have published them. At any 

 rate, he evidently thinks that the phosphates in manure are ren- 

 dered more soluble by fermentation." 



" Perhaps," said I, " we can not do better than to let the matter 

 rest in that form. I am merely anxious not to draw definite con- 

 clusions from the facts which the facts do not positively prove. I 

 am strongly in favor of fermenting manure, and should be glad to 

 have it shown that fermentation does actually convert insoluble 

 phosphates into a soluble form." 



There is one thing, however, thit these experiments clearly 

 prove, and that is, that there is a far larger quantity of soluble 



