ON THE MILK OF THE COW. 
315 
It seems to follow, from these facts, that an animal fed upon dry hay requires an amount of 
water, at least, which will be sufficient to restore the water to the hay which was lost in drying, 
or in being changed from grass to hay. 
To prosecute, successfully, experiments which I am about to detail, requires a subject which 
is gentle and composed ; a cow which is restless, and of a nervous temperament, will, espe¬ 
cially under confinement, become impatient and fretful ; one too, which is naturally wild, will 
always be a bad subject, and her milk will vary, probably not only in amount but very proba¬ 
bly in quality also, from trivial circumstances, and independent of the quality of her food ; 
analogy points to such a result. It is well known that the milk of the female of our own 
species is invariably changed by circumstances, and to that degree, in a few recorded cases 
where the influence was of a moral kind, that death of the infant has followed from its imme¬ 
diate use of the parent’s milk, and while under those influences. My cow, I believe, possessed 
the requisite qualities toffit her for the objects I had in view. She was docile and gentle, and 
easily milked, and though not at all remarkable for the quantity, she habitually gives, yet the 
quality has always been remarkably good, especially in the quantity of butter which it has fur¬ 
nished at different times. I think, too, that her system feels at once the effect of the food, and 
that it is not lost or dissipated in unproductive matters, but supplies it with sustenance which 
is expended in keeping it w r arm and supplying wants which have resulted from the ordinary 
waste of the system, and which is not excessive from extraneous circumstances. The opinions 
of physiologists have not coincided in respect to the influence of food upon the quantity and 
quality of milk. Boussingault maintains that it is not essentially affected in quality and 
quantity, provided each kind of food is administered in equivalent proportions, or which is 
about the same thing, provided we give the more watery and poorer kinds of food in such 
quantities that its poorness is made up in quantity. This opinion, however, does not seem to 
be sustained by Thompson’s experiments, made by order of the British government; and my 
own experiments, so far as they are made in the same line with those of Prof. Thompson, go to 
sustain his results : beside, it is a natural view to take of the matter. Milk is derived from the 
food, and it must partake substantially of its properties. It is not a substance, properly speak¬ 
ing, which is created, but compounded of preexisting elements. If there is a deficiency of one 
element in the food, we may well suppose that the milk will contain less of it. Some kinds of 
food must make more cheese than other kinds : some pasture lands of this State make, all things 
being equal, better butter than others. But there is undoubtedly a limit to the influence of 
food upon this secretion. There is a capacity of gland or organ which limits its capabilities; 
it has its capacity determined by its growth; it is an individual organ, and it is, as it were, 
guaged by the constitutional peculiarity, and any increase of food, beyond a certain amount, of 
whatever composition it may be, can not affect the secretion beyond a certain limit. Proba¬ 
bly the law of her constitution can not be controlled, certainly with safety. The object which 
the farmer must have before him is to keep his animal up to her full capacity, without carrying 
his stimulus for milk beyond that point. The secretion is not so much influenced by food as 
that of the kidney : but disease, in both cases, modifies the products of these glands. In the 
