Thickening agents. — As indicated above, the adulteration of milk 
through the use of thickening agents, such as chalk, calves 7 brains, 
glycerin, etc., has largely passed out of vogue. Indeed it is doubtful 
whether any of these substances were ever used to any considerable 
extent, despite traditions to the contrary. According to Van Slyke 
(5) gelatin and sucrate of lime are used to some extent to give a 
greater consistency to cream. In this connection Babcock and 
Russell have recommended the use of sucrate of lime for restoring 
the consistency of pasteurized cream. (See Leach, p. 156.) Con- 
densed unsweetened skim milk has also been employed as an adul- 
terant, with the object of increasing the consistency and raising the 
total solids of a skimmed or watered milk. 
The addition of substances with the view of altering or disguising the 
taste of milk or of increasing the total solids. — Milk is sometimes adul- 
terated by the addition of certain substances intended to alter or dis- 
guise the taste of milk. These are sodium carbonate and bicarbonate, 
cane sugar, and saccharine. Sodium carbonate and bicarbonate 
are sometimes added to sour milk with the view of neutralizing the 
lactic acid and preventing or delaying the separation of the curd. 
Cane sugar is added in order to increase the amount of total solids in 
milk impoverished by watering, and also to increase the sweet taste 
and thereby disguise any slightly sour taste which old milk may pos- 
sess. Saccharine is sometimes added to milk for the same purpose. 
It not only increases the sweet taste of milk, but probably also acts 
as a mild antiseptic. While all of these substances are probably 
harmless in the amounts in which they are employed in milk (cer- 
tainly the addition of cane sugar can ordinarily do no particular 
harm), the practice of adding these substances to milk is to be con- 
demned, mainly on the ground that they are rarely used except 
to conceal deficiencies in the quality of the milk itself, thereby 
enabling the dairyman to palm off on the consumer milk winch 
ordinarily would not be found acceptable. 
Coloring matters. — Milk is sometimes adulterated by the use of 
artificial coloring matters. The principal object to be accomplished 
by the use of these colored substances is to conceal other forms of adul- 
teration, such as skimming and watering, and to make the milk 
appear richer than it really is. It has been pointed out in the fore- 
going that skimming and watering cause an alteration of the color of 
milk as compared with normal milk. Generally milk that has been, 
skimmed and watered is more whitish in color than milk containing 
the normal quantity of cream. In order to conceal these deficiencies 
in the color of milk so adulterated various artificial coloring matters 
are added in order to bring the milk up to the color of normal milk. 
Among the coloring matters which have been employed for this pur- 
pose are annotto, certain of the yellow and orange-colored azo dyes, 
