Chemical Chaurjes in the Fermentation of Danrj. 337 
unemployed would serve him no more than his neighbours. The 
nitrogen in it would escape as carbonate of ammonia into the 
atmosphere, and a mere carbonaceous residue of decayed plants 
would after some years be found in its place." — Agricultural 
Chemistrg, p. 83. • 
An extreme case often illustrates an argument more powerfully 
than an ordinary one, and though no person is so foolish as to 
leave manure till it have diminished to this " small carbonaceous 
residue," yet it must be remembered that the process which ac- 
complishes such a result is a gradual one, and that every day brings 
it nearer. They who lay most stress upon atmospheric carbon 
admit that an ordinary soil becomes increasingly productive with 
its increase in carbonaceous matter derived from manure and the 
remains of plants, icliatever be the cause of this. Here then is 
([uite ground enough for an appeal to the practical farmer to 
husband his carbon as Avell as his nitrogen ; or rather in saving 
the one to prevent loss of the other. 
Albuminous substances contain a certain quantity of unoxidized 
phosphorus* (jMuldei") which must enter into combination with 
some one or more of the liberated elements which abound when 
these substances are fermented. With which element is a question 
of some moment to the farmer, because salts of this body are cer- 
tainly among the most valuable substances which he can add to 
his land as manure. The effects of burnt bones and superphos- 
phate of lime are familiar proofs. If the phosphorus of albu- 
minous compounds unite during fermentation with oxygen as we 
find it in the ashes of plants it forms phosphoric acid, a non- 
volatile body of great value as food for plants ; but if toith hydro- 
gen it forms a volatile substance, phosphuretted hydrogen, which 
will fly off and in the end benefit some one, but certainly not the 
person who has been at the expense and pains of its production. 
Popular opinion will no douljt at once join this })hosphorus 
with oxygen and regai'd any other view with surprise. Tlie com- 
mon mode of determining phosphorus in plants, viz. by ignition 
and estimation from the ash as phosphoric acid, would be urged 
by most persons as conclusive. 
But this opinion seems to be taken up without adequate know- 
ledge. Tliat part of the phosphorus of jiutrefylng organic com- 
pounds unites with hydrogen and forms the volatile body phos- 
phuretted hydrogen is certain. It can be detected even by the 
ordinary and inexact sense of smell. The foetor of putrefying 
albuminous bodies such as jjlood Is due to this gas as well as to 
sulphuretted hydrogen, and it Is doubtful whether any organized 
* " It has long been known that the protein compounds, of both animal and 
vegetable origin, contain sulphur and phosphorus in an vinoxidized state." — Rose's 
Paper before the Royal Academy of Berlin. ' Chemical Gazette,' vol. v. p. 158. 
