Experiments on the Fccdinj of Stock. 
443 
hog," would itself seem to point to a short-eared, bearded 
variety, such as is not much in favour with millers. But further; 
Mr. Lawes and other authorities, whilst they recognise the high 
importance of a certain portion of the food being rich in nitrogen, 
do not consider that any proportional benefit will be derived from 
increasing- this element bevond verv moderate limits. 
It would seem that both in the soil, in the plant, and in the 
animal, nitrogen mav be considered as a stimulant ; that is, as an 
agent which calls actively into plav the services of other bodies, 
besides, or insteatt of, taking a part in the work itself. In the 
soil it renders mineral substances assimilable, or, as Liebig terms 
it, brings them from a state of chemical, into one of physical 
combination. In buildinsr up the plant, according to the same 
authority, it would seem that nitrogen acts in part as a moulding 
power, which, when one cell is completed, transfers its energy to 
the formation of a second, leaving but little of its own substance 
built in among the particles v/hich it has brought to coalesce 
together. So, further, a writer in the Bavarian ' Centralblatt,' of 
1861 (p. 224), writes that " the nitrogen in rape-cake renders 
assimilable the masses of fodder, which otherwise would be 
driven through the animal to no effect — a doctrine which the 
striking effects produced by supplementing sewage-gi-ass with a 
little oil-cake in the Rugby experiments, tend to confirm.* If, 
then, on the one hand, it mav be verv bad policy to leave anv 
animal at any age on any keep without some small quantity of 
food rich in nitrogen, — on the other hand, the rule, that nutrition 
varies as the nitrogen supplied, mav have verv definite limits, 
and no good may be gained by passing beyond these, since it is 
probable that in the last stage of fattening stock the fatty matter 
especially is associated little by little with the nitrogenous ele- 
ments, in the same manner as ^I, Reiset tells us the starch is 
accumulated in the final development of the grain. 
Opinions such as these appear to be gaining ground among 
English 'agriculturists, and the ready acceptance which these 
limitations meet with tends to show that they are not so blindly 
prejudiced and obstinate as they have been represented. In 
stock-feeding they gladlv modify their views as to the requisite 
supply of nitrogen ; and for manuring their lands, if they could 
only meet with satisfactory evidence on practical authority, they 
would act in the same manner, and would be only too glad to limit 
a costly investment which much interferes with profit. 
But M. Reiset not only employs the nitrogen standard as a 
means of contrasting two kinds of wheat, but also for instituting a 
comparison between meat and bread as food for man. That we 
* See Report, 1862. 
