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 of 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 3 '83 



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. 



