58 Composition of Cheese. 
whey is very milky in appearance, yet as a rule this loss is small 
in most dairies. Indeed, my analyses prove positively that whey 
seldom contains much casein or curd which might be retained 
by ever so careful filtration. 1 have filtered whey from good 
milk through the finest blotting-j)aper, and obtained it as bright 
as crystal. On heating the perfectly clear whey to the boiling- 
point, however, a considerable quantity of a white, flaky sub- 
stance, resembling in every respect albumen, or the white of egg, 
made its appearance. Collected on a filter, washed with distilled 
water, dried at 212° F., and weighed, this albuminous or curdlike 
substance amounted on the average to aliout '9 or nearly 1 per 
cent, in good milk ; in very rich milk there may be a little 
more, in poor a little less. This albuminous matter is contained 
in the whey in a state of perfect solution, and differs from casein 
or curd in not being coagulated by rennet. I have called it an 
albuminous matter, because, like albumen, it separates in flakes 
from the whey at the temperature of boiling water. Any one 
may prove the existence of this substance, Avhich, however bright 
the whey may be, it invariably deposits in abundance at the 
boiling-point. 
Assuming, then, '9 to be the average proportion of this albu- 
minous matter in whey, and deducting this proportion from the 
total amount of nitrogeaized substances in the eighteen samples 
of whe3-, we obtain the amount of curd held in mechanical sus- 
pension. Thus we get for 
No. 1 whey 
No. 2, 4, 8, and 15 whey.. 
No. 3 and 13 whey .. 
No. 5 whey 
No. C and 9 whey 
No. 7 whey 
No. 10, 12, and Id wliey .. 
No. 11 whey 
No. IC, 17, and 18 whey .. 
'30 per cent, of curd, held in a state of 
mechanical susjieusion. 
none. 
•OG per cent, of curd, held in a state of 
mechanical suspension. 
•525 per cent, of curd, held in a state of 
mechanical suspension. 
•11 i)ei' cent, of cmxl, held in a state of 
mechanical suspension. 
•15G 2)er cent, of curd, held in a state of 
mechanical suspension. 
•01 per cent, of curd, held in a state of 
mechanical suspen.sion. 
•03 jjer cent, of curd, held in a state of 
mechanical suspension. 
•04 per cent, of curd, held in a state of 
mechanical suspension. 
Thus only in one sample out of eighteen there was about ^ per 
cent, of curd held in mechanical suspension, and one sample 
containing -,Vths per cent., all the other samples, pi'actically 
speaking, containing no suspended curd. Thus it is not so much 
the curd as the butter which is lost when whey is badly separated 
from the curd. 
