On the Chemistry of Ensilage. 
499 
Dried at 
i 212= Fahr. 
94-63 
1-50 
27-93 
•88 
16 "39 
1-29 
23^99 
1-70 
3r69 
100-00 
100-00 
•24 
4-47 
The drainage-liquids from silage made from succulent green 
food, when too great a weight is placed on the top, it will be 
seen, is rich in albuminous and soluble non-nitrogenous food- 
constituents, and therefore ought not to be allowed to run to waste. 
In none of the samples of silage which have been brought 
under my notice was I able to detect even traces of alcohol. It 
must, however, be borne in mind that all the samples were 
received by me in a comparatively advanced stage of preparation, 
in which most were strongly acid. The few samples which 
were sweet and free from acid had not, I think, undergone 
alcoholic fermentation ; but the samples in which I found 
from ^ to 1 per cent, of acetic acid had, I believe, all passed 
through alcoholic fermentation ; and had they been examined at 
an earlier stage of preservation, small quantities of alcohol would 
have been found, for the production of acetic acid is always 
preceded by the production of the peculiarly pungent and 
aromatic-smelling volatile substance known to chemists by the 
name of aldehyde. In fact, acetic acid is readily formed by 
allowing free access of air to porous materials impregnated 
with the vapours of aldehyde. Acetic acid may be described 
simply as a product of oxidation of aldehyde, which in its turn 
is generated from alcohol, by the abstraction of a definite pro- 
portion of its hydrogen. 
When sweet vegetable juices enter into alcoholic fermentation, 
the sugar contained in them is converted more or less completely 
into alcohol and a number of by-products, according to the 
conditions in which the fermentable liquids are placed and 
the fermentation is regulated as regards temperature. 
At a certain stage of the process of ensilage I have often 
noticed that silage smells strongly of aldehyde ; but this smell 
soon passes off, and in its place acetic acid makes its appearance. 
As a rule, I find the nitrogen in silage occurs not only in 
the form of albuminoids, but also in variable proportions as 
