I2 MILK 
on account of the liability of the upper layer 
of the liquid to be richer in fat than the lower; 
the overflow, therefore, does not represent the 
mixture. 
Total Solids.—This determination may often 
be made with sufficient accuracy for practical 
purposes by evaporating a measured volume 
(e. g., 3 or 5 c.c.) in a shallow nickel dish from 5 
to 8 cm. in diameter. Nickel crucible-covers are 
suitable. The thin glass (Petri) dishes used for 
microbe culture are convenient. When greater 
accuracy is required, and especially when the 
ash is to be determined, platinum dishes are the 
most satisfactory, but owing to the present price 
of this metal, quartz dishes are now much used. 
Either the translucent or transparent quartz is 
suitable, the former being less expensive. 
Good results may be secured as follows: A flat 
dish, 3.5 cm. in diameter, with sides 0.5 cm. high, 
is provided with a thin flat watch-glass cover 
that fits rather closely. The total weight of the 
cover and dish is noted. 2 or 3 c.c. of the sample 
are run into the dish from the pipet, the watch- 
glass placed on, and the weight taken as rapidly 
as possible. The glass prevents appreciable 
loss from evaporation during an ordinary weigh- 
ing. The cover is removed, the dish heated on 
the water-bath or in the water-oven, and weighed 
from time to time (with cover on it) until the 
