NATURE OF DEPOSIT OBTAINED FROM MILK. 161 
It will be seen from the preceding table that there is con- 
siderable variation in the ash-content of these deposits. 
The extreme values for the percentage of ash in the deposits 
being 6°80% and 9°87. As will be seen below this varia- 
tion is to be attributed in part to differences in the times 
for which the milks were spun to obtain the deposits. 
Variation of ash-content of deposits with time of spin- 
ning.—Not only are there differences between the ash- 
contents of the deposits from different milks, but deposits 
from the same milk show different percentages of ash accord- 
ing tothe time for which the milk is spun before collecting 
the deposit. Samples of deposit after various periods of 
spinning were got by stopping the centrifuge at the appro- 
priate times, pouring the superfluid off the deposit into a 
clean tube, and putting this on to spin again to obtain the 
deposit corresponding to that coming down at the later 
period. The following table shows the variation of the 
percentage of ash of the deposit with the length of time 
for which the milk is spun. 
TableV —Variation of percentage of ash of deposit with time of spinning. 
Milk. Period. Wt. of Deposit.) Weight of Ash. |Percentage Ash. 
19 30 min. 0°2568 gm. | 0:0177 gm, 6°89 
Lp ae 0°4407 _,, 0:0349 _,, 7°92 
Lt ae OSLO) 4; C0250 7°30 
ZA O21 775. ¢ O-O108. |; 6°08 
22 ee G2 700 5, 00231 ,, 6°24 
1a, 0°2508 _e,, 0:0203. _, 8°09 
195 5, G-20 58. O:015S) 55 7°46 
ZOOs fs O-Moe 14, O;O Taras: 6°55 
23 60; 0:2935 |; 0:0250 ,, 6°36 
£50 (:,; 0°2854 _,, 0:0200 ,, fora! 
£93.) ., 0°2051 _,, C0133 .,, 8°49 
Zhe O2070- D022; 8°50 
24 60 ,, 0:2642 ,, | 0:0220 ,, 8-32 
ra Q-1604. ,, COLT ,, 8°54 
£60 ~,, 0°1545 >; CORE’ 5; 57 
234, 0°1632 _,, 0:0130 (OEM 
K—July 1, 1914. 
