at Home and Abroad. 
243 
example of the former, and Mr. Trepplin's numerous samples of 
silage of different crops of the latter. I do not know that it is 
a great object, except on large sewage-farms, that silage should 
keep good after exposure to the air for more than a week or two. 
If the fodder be cut in slices not too thick for ordinary re- 
quirements, the new face is not exposed long enough for any 
considerable deterioration to take place. Therefore the main 
point for the farmer is to obtain his silage only so much fer- 
mented as will enable him to use it to the best advantage, and 
this I conceive to be the alcoholic stage. 
Hitherto I have spoken only of the effect of fermentation 
in breaking up the starch, gum, &c., into alcohol and other 
products ; but chemists seem to believe that the nitrogenous 
materials which act as a ferment are also themselves more or 
less decomposed. It is considered that the value of these 
nitrogenous materials as flesh-formers is thereby impaired ; 
but in the present state of the question it is unnecessary to 
discuss it further in this Report. 
The effect of the fermentation on the woody fibre is, however, 
better understood, and is, moreover, of greater practical import- 
ance. Dr. Voelcker showed, in the volume of this ' Journal ' 
for 1871,* that the effect of fermentation on the straw-chaff 
preserved by Mr. Jonas's method was to convert a large pro- 
portion of the indigestible woody fibre into digestible material. 
On this point he observed : " In the cases before us, it will be 
seen that, of the total amount of vegetable fibre present in the 
fermented wheat-chaff, 45f per cent, were rendered soluble by 
the treatment described, and 34^ per cent, (in round numbers) 
left behind as indigestible woody fibre, whilst the 73J per cent, 
of vegetable fibre present in common wheat-straw chaff were 
resolved . . . into 19^ per cent, only of digestible, and into 
54 per cent, of indigestible, woody fibre. In other words, the 
same treatment rendered soluble 50"85 per cent, of the vegetable 
fibre of the fermented prepared chaff, and only 2 6 "38 per cent, 
of the fibre of common wheat-straw." 
The construction of a Dr. and Cr. account as between the 
loss of feeding material occasioned by the conversion of carbo- 
hydrates into alcohol and acetic acid on the one hand, and the 
gain of feeding material by the conversion of indigestible into 
digestible woody fibre on the other, is a question for the 
chemical accountant, and no doubt such a balance-sheet will be 
shortly forthcoming.! To the farmer, however, the " proof of the 
pudding is in the eating ; " and whatever may be the result of 
* ' On the best mode of preparing Straw-chaff for Feeding Purposes.' Second 
Series, vol. vii., p. 85. 
t Vide remarks by Mr. Betley on p. 157. 
R 2 
