MANURES. 77 



amount of soluble organic matter to interfere sadly with the nitric 

 acid determination ; and unable to supply for the present correct 

 results, I merely mention the fact that these liquids contained 

 nitrates, and trust to be able to supply this deficiency in these 

 analyses at a future period. In the next place, I would observe, 

 that the proportion of organic and inorganic matters bear to each , 

 other different relations in the first and in the third liquid. 



In the liquid from rotten dung, the proportion of mineral matter 

 exceeds that of organic substances, and, in the third liquid, the 

 reverse is the case. We learn from this that soluble organic mat- 

 ters are very liable to become decomposed ; and it is not unlikely 

 that all putrescent organic matters, before assuming a gaseous 

 state, are first changed into soluble matters. 



In the first stage of decomposition, i. e., during the active fer- 

 mentation of dung, the constituents of farm-yard manure are ren- 

 dered more and more soluble ; hence, up to a certain point, the 

 amount of soluble organic matters increases in manures But 

 when active fermentation in manure heaps becomes gradually less 

 and less energetic, and finally ceases, the remaining fermented 

 manure is still liable to great and important changes, for it is sub- 

 ject to that slow but steady oxidization or slow combustion, which 

 has been termed appropriately by Liebig, Eremacausis. To this 

 process of slow oxidation all organic substances are more or less 

 subject. It is a gradual combustion which terminates with their 

 final destruction. 



Hence the larger portion of organic matter in the liquid from the 

 manure heap formed of fresh dung in an active state of fermenta- 

 tion, and the smaller portion of organic matter in the drainings of 

 the first heap, in which the dung had passed the first stage of 

 decomposition, and been exposed for a considerable period to the 

 subsequent process of eremacaucis or slow combustion. The forma- 

 tion of nitric acid from putrefying organic matter has long been 

 observed, but the exact condition under which it proceeds, are by 

 no means satisfactorily established, and much room is left to furth- 

 er extend investigations. 



The mineral substances in the drainings from fresh dung are the 

 same as those from rotten. Like the ash of the latter, the liquid 

 from fresh dung-heaps contains soluble phosphates, soluble silica, 

 and is rich in alkaline salts, especially in carbonate of potash, of 

 which there are nearly 300 grs. in a gallon of the liquid. Sufficient 



