242 
Report on the Practice of Ensilage, 
frequently described as like burnt sugar, Cavendish tobacco, 
&c. (Sec. It is somewhat remarkable that very few samples of 
silage have yielded to the analyst more than traces of alcohol, 
although by their smell one would think them saturated with it. 
This is due to the powerful odour of the aldehyd, which may, in 
common language, be regarded as partially burnt alcohol. If 
the air has not been properly expelled from the silo, or if the 
fodder has been pitted very wet, the aldehyd rapidly becomes 
converted into acetic acid, otherwise vinegar. And so by this 
roundabout process we get a saner-kraut, or pickle, by a much 
more destructive and therefore expensive system than by means 
of the direct lactic fermentation.* 
The farmer will doubtless want to know how to control these 
various changes, and which is the best condition for his silage 
to remain in. As we have not the summer heat of the grape- 
growing districts of France, we cannot hope to grow maize, and 
other fodder crops containing a large percentage of sugar, over 
the greater part of England ; and this consideration has retarded 
the use of ensilage for crops having a small percentage of sugar, 
not only in England, but also in France and America. It is 
only of late years that these crops have been preserved by 
ensilage. In the case of our own fodder crops, the evidence 
given in the foregoing pages tends to show that crops cut before 
they begin to get woody (in other words, while they are still 
full of sap), pitted after having been chopped, then carefully 
trodden layer by layer, then covered with boards, and mode- 
rately weighted, stand the best chance of not going much 
beyond the alcoholic fermentation. On the other hand, crops 
put in unchopped, dripping with wet, imperfectly trodden, and 
no matter how heavily weighted, will rapidly go through all 
the processes, and even beyond those I have spoken of, namely, 
into the putrefactive stage. 
Speaking from experience gained by the examination of 
a large number of samples of silage, the facts attending which 
I have given in the preceding pages, I may state broadly with 
regard to their keeping qualities, that the saner-kraut, or pickle 
stage, will keep the longest, and the almost non-fermented 
samples the shortest time without becoming mouldy, j Samples 
emitting the characteristic smell of aldehyd will keep good for 
some considerable time if they are dry, but rapidly go bad if 
they are wet.f Mr. Garrett Taylor's sewage-grass silage is an 
* See Mr. Smetham's note on p. 383 for an explanation of the changes which 
took place in the fodder pitted in Lord Egrrton's silo. 
t Compare Heer van der Breggens s-tatement on p. 223. 
X The smell of aldehyd often remains long after the substance has been con- 
verted into acetic acid. In fact, aldehyd has never, I believe, been detected iu 
silage, on account of the transient nature of its existence. . 
