319 
contains, and to its influence on the health of the child. Camerer 
(22) found 21 milligrams of iron oxid in 100 cubic centimeters of 
human milk from the third to the twelfth day of lactation. Accord- 
ing to Jolles and Fried jung (23) the quantity of iron in human milk 
decreases with bad environment and poor condition of the mother. 
In certain diseased conditions milk may contain still other sub- 
stances not ordinarily present in the milk of healthy animals. For 
example, Yan der Marck (24) has detected bile in the milk of a 
woman who had developed jaundice after confinement, and Des- 
moulieres and Gautrelet (25) have, found that the so-called lipo- 
chrome of cow’s milk consists almost entirely of urobilin. Still other 
substances are sometimes acquired by milk either from the food of 
the animal or from its environment after its removal from the animal. 
Bordas and Touplain (26) have shown for example that milk rapidly 
absorbs certain odoriferous substances from the air, and Dombrowski 
(27) has shown that the odor and flavor of certain seeds and plants 
are imparted to the milk b} T feeding with these substances. An 
excellent example of this is furnished in the case of garlic. Ac- 
cording to Rosemann (28) alcohol passes into the milk when admin- 
stered to an animal in large amounts. Similarly Teichert (29) ob- 
served that the milk of cows fed 90 per cent “ slump ” contained fusel 
oil and that calves fed with such milk died. According to Bechamp 
(30) even freshly drawn milk contains recognizable amounts of 
alcohol and acetic acid. Golding and Feilmann (31) detected copper 
in a certain milk supply, and have shown that in the presence of air 
milk has the power of dissolving small quantities of this metal. 
In addition to the substances already mentioned, normal milk con- 
tains a number of enzymes, such as diastase (amylase), galactase, 
lipase, catalase, peroxidase, reductase, etc. The presence of these 
ferments serves to distinguish raw from boiled milk. According to 
Marfan and Gillet (32) milk is not an inactive fluid, but possesses 
certain properties peculiar to living substances. According to these 
authors it contains ferments and gives Bordet’s reaction (see p. 335), 
which reaction is not shown by dead material. It also shows Moro’s 
reaction (see p. 335). These specific ferments of milk and its char- 
acteristic biochemical reactions will be considered at length under 
milk enzymes (see pp. 335 to 342). 
IVoodhead and Mitchell (33) have recently shown that milk also 
contains opsonins in even greater quantity than blood serum. It 
also contains alexins and bactericidal substances. According to 
Brieger (34) and his coworkers, the milk of animals immunized 
against diphtheria and tetanus contains antitoxins. 
A very good idea of the quantities of the several more important 
substances contained in milk may be obtained from the following 
schemes compiled bv Lucius L. Yan Slyke (35) and S. M. Babcock 
(36): 
