Composition and Nutritive Value of Straw. 
391 
extent un(li<?estod wlien given to .mother. Thus it has beiMi 
proved by direct experiments tliat cows can extract a j^reat deal 
more nourisliment from straw-cliafF than horses, and that sheep do 
not appear to digest chafl' so readily as cattle. 
Although chemical analysis cannot decide -with anything like 
precision the most interesting and practically important point on 
whicli the whole controversy of the feeding value of straw hinges, 
we must not suppose that it is altogether useless to submit to 
analysis the various kinds of straw used on the farm. I hope to 
be able to show that the investigation undertaken by me at the 
request of the Chemical Committee of the Royal Agricultural 
Society has brought to light several matters of considerable 
practical importance, and is suggestive of others of interest. 
The following points, at all events, can be readily ascertained. 
In the first place, we can determine with precision the amount 
of oil, certainly the most valuable constituent of straw ; secondly, 
the proportion of albuminous or flesh-forming matters ; and thirdly, 
the amount of organic substances soluble in'water, such as sugar, 
mucilage, gum, extractive matters, &c. The mineral portion or 
ash, of course, is easily ascertained by burning a known quantity 
of straw in a platinum capsule, and Aveighing the ash which 
remains behind. 
The proportion of oil is easily obtained by exhausting a 
weighed quantity of straw in an appropriate apparatus with 
ether, and evaporating the ethereal solution of oil to dryness. 
Albuminous compounds are now usually determined in the 
indirect manner by combustion with soda-lime, and multiplica- 
tion of the percentage of nitrogen by (jj. A weighed quantity, 
exhausted with cold and afterwards with boiling water, produces 
the proportion of soluble matter, consisting of sugar, mucilage, 
extractive matter, and soluble saline matters. If the portion of 
straw previously exhausted with ether and water is subse- 
quently boiled with a solution containing 1 per cent, of caustic 
potash, the insoluble albuminous compounds are dissolved ; 
and by treating the residue left after boiling with potash-solution, 
with dilute sulphuric acid, and finally washing again with water, 
we obtain the amount of cellular and woody fibre in the straw. 
It has been stated already that this process does not furnish 
corresponding results in two or three separate determinations. 
Nevertheless it is desirable in detailed analyses to have recourse 
to this process, which at least allows us to form some idea of the 
readiness with which the part of straw which is insoluble in 
water, and which may be termed crude woody fibre, is attacked 
by dilute alkalies and acids. There can be no doubt that the 
different alkaline and acid secretions in the animal organism 
