ON THE MILK OE THE COW. 317 
I obtained comparable results, notwithstanding organic matters are not so susceptible of accu¬ 
racy as inorganic, as a general rule. 
I shall now proceed to the details which are intimately connected with the analyses of milk. 
In the first place, it is necessary to state that the cow was feeding upon the grass of the pas¬ 
ture, which was not very abundant—middle ot November ; but to make up any deficiency there 
might be in the feed, pumpkins were given every day, which did not appear to add to the 
quantity of milk the cow was giving at the time. The milk, as I have already stated, was 
always of the kind which is called rich. It had the following composition while the animal 
was feeding upon grass : 
Specific gravity, 1032. 
Water,. 85*80 
Solid matter,.• ••• 15*55 
Butter,. 5*76 
Casein,. 5*02 
Sugar and extract, ... d'Sd 
A quantity of the same milk was churned ; it gave per pound of milk 457 grains of butter, 
which is equivalent to about 5*9 per cent, after deducting the casein. 
The composition of grass, cut past the middle of November, is as follows : 500 grains gave, 
on being well dried in a water bath, 160*4 grains : ash, 11 * 32. 100 grains of this dried grass 
gave, 
Chlorophyl, or wax,. 5*08 
Sugar and watery extract. 21*60 
Fibre,. 73*32 
The ash, or inorganic matter, contains, 
Silex, . 46*12 
Earthy phosphates,. 16*20 
* Carbonate of lime,. 10*60 
Magnesia,. 0*86 
Potash,. 14*63 
Soda,... 9*40 
Sulphuric acid,. 0*47 
Chlorine,. 0*06 
The ash of milk gave nearly 50 per cent of earthy and alkaline phosphates, or 1*48 in 3 
grains. This analysis of the ash of grass, is not given so much for the light that it throws on 
the composition of milk, it is given for the purpose of showing the composition of grass at this 
season of the year. The chlorophyl, which is of the nature of wax, is supposed, by Prof. 
Thompson, to be used or consumed in respiration, and is not employed in the formation of milk ; 
the excess which remains after this expenditure, is found intermixed with the solid excrements, 
in an unchanged condition. The sugar and soluble parts in water, as albumen, furnish the 
materials for the milk. 
