344 
These observations on galactase have been fully confirmed by Von i 
Freudenreich (9) and other investigators (10). ^Vender (11) has 
shown, however, that galactase as ordinarily prepared from separator 
slime, according to Babcock and Bussell’s method, in reality consists 
of at least three distinct enzymes, viz, gallactase proper, peroxidase, 
and catalase. Ordinarily galactase by itself acts too slowly to cause 
any material change in the proteids of milk in the short intervals 
which usually elapse between the withdrawal of the milk from the 
animal and its consumption as food. It is claimed by Babcock and 
Bussell, however, that this enzyme probably assists in those changes 
which ordinarily take place in the ripening of cheese. It is also 
claimed by Snyder (12) that when milk is used in a mixed diet the 
proteids have been found to be from 4 to 5 per cent more digestible 
than when milk is omitted from the diet. This increased digestibility 
he claims is due to the milk enzymes. In this connection, it is of 
interest to note that Hougardy (13) has recently shown that cow’s 
milk contains a ferment or a kinase similar to enterokinase. The 
author proposes to call this ferment lactokinase. This lactokinase 
has been found to accelerate the digestion of proteids by pancreatic 
juice and loses its power to facilitate this change at 73° to 75° C. 
Lipase. — Marfan and Gillet (14) found a lipase in milk capable of 
hydrolyzing monobutyrin. Human milk exhibits this property to a 
higher degree than cow’s milk. The former was found to have a 
lipolytic activity of 20-30 on Hanriot's scale, while cow’s milk shows i 
an activity of only 6-8. Gillet (15) has shown that the milk of differ- 
ent animals contains the lipolytic ferment. This ferment withstands 
cold, but is destroyed by heating to 65° C. It is nondialyzable and is 
held back by the porcelain filter. It probably hydrolyzes the higher 
fats of milk at least to some extent and may possibly account for a 
small part of the acidity of sour milk. 
In this connection Bogers (16) has observed that this ferment is 
present in butter and on standing increases its acidity. 
The so-called “ salol- splitting ferment T — Nobecourt and Merk- 
len (17) observed that human and ass’s milks have the power of hy- 
drolyzing salol (phenyl salicylate). For a time this hydrolysis was 
believed to be accomplished by an enzyme, to which the name of “ the 
salol-splitting enzyme ” was given. It was afterwards shown, how- 
ever, by Desmoulieres (18) and also by Miele and Willem (19) that 
no such ferment exists in milk and that this decomposition of salol is 
in reality a saponification brought about by the alkali present in cer- 
tain milks, and that only those milks having an alkaline reaction are 
capable of effecting this decomposition, so that this probably disposes 
of this subject. 
The oxidizing ferments of milk . — Milk contains no true oxidases or 
oxidizing ferments proper. It does decompose hydrogen peroxide, 
