No. 144] 501 



supply, was in the case of carbonic acid to the decay of manures 

 in the soil, so to this process of disintegration do we owe all our 

 available stock of ammonia. Liebig has demonstrated the pre- 

 sence of this, the volatile alkali, in rain water; but this source of 

 it is probably connected with the emanating of it from the bodies 

 of animals and their excrements. It is absorbed to even a greater 

 extent than carbonic acid by the earthy and organic constitutents 

 of the soil. In this way the copious supplies of it, given off by 

 the rapid decomposition of those substances containing it, are 

 reserved and gradually given out to the rootlets of plants. Char- 

 coal absorbs ninety times its own bulk of this gas, and humus has 

 almost an equal power -, burnt clay takes it up freely. The prac- 

 tical application of earth as a deodorizer in burying the carcasses 

 of animals, depends on its absorbent power. A few inches of earth 

 is sufficient to destroy all smell. Four pounds of gypsum can 

 absorb enough of this gas to supply one cwt.of grass with it, and 

 it was for a long time supposed that it was in this way alone that 

 that substance stimulated meadows. 



Of the ultimate sources of ammonia little is known. It was at 

 one time supposed that it was derived directly from the nitrogen 

 of the atmosphere, but that idea is now generally given up. By 

 what forces the nitrogen and hydrogen atoms are united, we can- 

 not tell ; but we know that if the resultant compound gas (am- 

 monia) be poured through a red hot tube, these elements are sepa- 

 rated. We may, if we please, infer from this, that the atom is of 

 organic origin. Yet it forms no part of the constituents of healthy 

 animals, being generated by a fermentation, and it exists as am- 

 monia in few if any plants, being used in them towards forming 

 their azotized parts. We have yet to trace this atom through its 

 various states and conditions, through its various forms and com- 

 binatioLS in animals and plants. We have yet to ascertain whence 

 it comes, and whither it goes. Does it remain with us year after 

 year in some form or other, and will the importations of guano in 

 this way prove of permanent benefit to the country, or does it 

 return directly to the passive condition of the atoms of the 

 inorganic worlJ. 



