252 
The Applications of Physiology 
eradication of these two weeds would have at once restored the 
pastures to their proper condition. 
In London, Edinburgh, and Glasgow the system of stall-feed- 
ing cows is extensively practised. As I have never visited the 
London establishments, I shall confine myself in my description 
to the Scotch method^, though I presume both are nearly the 
same. It is usual to allow the cows to pasture during the 
summer months, when the weather is propitious. Although the 
exercise thus received tends to diminish the quantity of butter in 
the milk, a greater flow of milk is really obtained, as their di- 
gestive apparatus is kept in a healthy state, and their appetite 
consequently increased. When kept in stalls they are fed upon 
grains, and allowed daily a few pounds of bean-meal. All the 
Scotch dairymen assured me that beans formed the most valuable 
food which they could give to stall-fed cows. The cows are per- 
mitted to drink as much pot ale (ale refuse) as they wish. 
Steamed turnips and potatoes are used as valuable additions to 
the preceding food. 
Now let us consider the theory of this method. Malt refuse 
contains starch, saccharine matter, a kind of mucilage, and a 
small quantity of albumen. The greatest part of the nitrogenous 
constituents have been removed ; hence the grains do not contain 
substances fitted for an abundant supply of casein, but for the 
formation of butter and sugar of milk they are admirably adapted. 
The beans furnished to the cattle contain casein ready formed, 
and therefore su])ply the deficiency in the previous food, while 
their starch and oil assist in the formation of the sugar of milk and. 
butter. The pot ale serves to increase the flow of the milk. 
Pure water does not readily enter the blood. We know that it 
destroys the blood-globules : but acidulous water does not do so, 
and this pot ale is acid ; it therefore enters the blood, and in- 
creases the flow of milk by diluting the secretions. It contains 
also alcohol, sugar, and starch, by means of which the respiration 
may be partly sustained, and the other food economised for the 
production of butter. The stalls in which the cows are kept are 
warm, and not too much exposed to light. The former econo- 
mises food ; and the latter condition does so likewise, by lulling 
the animals to repose. 
I have made a series of experiments in connexion with this lec- 
ture, in order to show the influence of food and exercise upon the 
secretion and composition of the milk of a cow. The cow was 
fed in the meadow and its milk analysed, and afterwards brought 
into the stall, its milk being in like manner subjected to analysis. 
The difference in composition was very marked ; the milk ob- 
tained in the meadow contained more casein and less butter, to 
the amount of several per cent., than that taken from the same 
