SOURCES OF PHOSPHORIC ACID. 173 



This shows the advantages gained by using dried 

 muck, around stables and enclosures where 

 cattle, sheep or hogs are kept, thus absorbing 

 and deodorizing the liquid and solid excrements. 

 Sometimes the application of muck in its 

 natural state, is not followed by any beneficial 

 effects, and in some cases it has been positively 

 injurious. This may be explained as follows : 

 All vegetable substances undergoing oxidation 

 or decomposition attain a seeming inert or fixed 

 state; and without the application or action of 

 some powerful agency, such as lime, will remain 

 in that condition for long ages ; and when sub- 

 jected to certain influences, such as heat and 

 great pressure, while in that state, will eventu- 

 ally form coal. We are indebted to this pro- 

 perty of decaying vegetable matter, for the vast 

 stores of peat and coal that are stored up in the 

 earth. Without this property, all organic sub- 

 stances would be speedily dissipated, as carbonic 

 acid gas, ammonia, etc. ; and even the mould, or 

 organic portion of soils, would be resolved into a 

 gaseous state and be dissipated in the atmos- 

 phere. Although this property of partially 

 decayed organic matter is the cause of its pre- 

 servation, it materially unfits it for the produc- 

 tion of cultivated plants, as it cannot, in this 

 inert condition, give out enough to support 

 them ; and it is not improbable that it imparts, 



