88 
Straw- Chdff for Feeding Purposes. 
Taking together digestible and woody fibre, we have in the 
fermented straw-chafF 70 38 per cent., and in ordinary wheat- 
straw 73"53 per cent ; showing a slight difference in favour of 
the fermented chaff, which, being richer in sugar and other 
matters soluble in water, contains about 3 per cent, less vege- 
table fibre than common wheat-straw. 
When the vegetable fibre of each kind of straw-chaff, or the 
material insoluble in cold and boiling water, is treated with 
dilute acid and alkalies of the same strength, for the same length 
of time, and in all other respects precisely alike, a certain pro- 
portion of the vegetable fibre is rendered soluble. This soluble 
portion figures in the preceding analysis as digestible fibre, 
whilst the matters insoluble after treatment with the various 
chemical agents is termed indigestible or woody fibre (Cellulose). 
Although it is not meant to convey by those terms the idea 
that animals have the power of resolving crude vegetable fibre 
into digestible and into woody fibre, in precisely the same ratio 
in which we can separate them in the laboratory, a tolerably 
good opinion may be formed of the relative digestibility of 
various foods consisting principally of vegetable fibre, by sub- 
mitting them to the process usually employed in laboratories for 
the determination of woody fibre. 
In the cases before us, it will be seen that, of the total amount 
of vegetable fibre present in the fermented wheat-chaff, 45|^ 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, by treatment with 
dilute acid and alkaline liquid, into 19J per cent, only of digest- 
ible, 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 
26*38 per cent, of the fibre of common wheat-straw. 
These differences are very marked, and well calculated to 
explain, in a great measure, the great inferiority of the fermented 
chaff as a feeding material over common straw-chaff. 
The fermentation to which the straw is submitted in Mr. 
.lonas's plan thus has the effect of rendering the hard and dry 
substance which constitutes the bulk of straw more soluble and 
digestible than it is in its natural condition. But useful as the 
effect of the slow and moist heat, developed in the mixture of 
straw-chaff with green rye or cut tares, no doubt is in rendering 
the fibre of the chaff more digestible, this is not the only recom- 
mendation of Mr. Jonas's admirable plan of preparing a really 
very nutritive and important food for stock. 
Another recommendation is the extremely delicate flavour and 
