ANALYTIC DATA 3 
are oxydases, that is, decompose hydrogen per- 
oxid and carry oxygen over to other substances. 
Lecithin is also a usual ingredient of milk. 
Nerking and Haensel found a range in cows’ 
milk from 0.03 to 0.11%. 
Mineral Matter.—The ash of milk contains 
calcium, magnesium, iron, potassium, and sodium 
as chlorids, carbonates, sulfates, and phos- 
phates. It does not exactly represent the salts 
present in milk. 
Richmond has determined the ratio of the 
ash to the solids not fat in 135 samples of milk. 
This was found to range from 7.8 to 9.4%, 
but more usually from 7.8 to 8.5 (average 8.2) %. 
Many ashes were alkaline to turmeric, litmus, 
and phenolphthalein, the maximum alkalinity 
being 0.025% calculated as sodium carbonate. 
Human milk is notable for a low protein 
content hence the curd is less bulky and more 
friable than that from cows’ milk. The milk 
of all animals is subject to modification by breed, 
climate, season, feed, housing, exercise, time 
of lactation, and in human beings (and possibly 
in some other animals) by psychic influences. 
As regards the proportion of proteins and 
lactose, milks of the mare and ass agree closely 
with human milk, 
Normal milk is an opaque white or yellowish- 
white fluid, with an odor recalling that of the 
