CHAPTER XVII. 
CULTURED MILK. 
Definition. The term cultured milk is applied to 
milk which has been soured by the use of special cul- 
tures of lactic acid bacteria among which, as a rule, 
is included the Bacillus Bulgaricus. Usually such milk 
is partially skimmed and then pasteurized before it 
is inoculated with the special cultures. When thor- 
oughly coagulated, the milk is agitated in a churn or 
other apparatus specially designed for this purpose, until 
it assumes a smooth, homogeneous consistency. 
Milk of this class is sold to the trade under various 
names, such as Bulgara, Pokoloc, Bacillac, Fermillac, 
Vitalac, Yoghurt, Zoulac, etc. 
Therapeutic Value. It was Dr. Metchnikoff of the 
Pasteur Institute who first proclaimed the full virtues 
of this class of milk, especially that soured with the 
Bacillus Bulgaricus, which is the name applied to a 
species of lactic acid bacteria indigenous to Bulgaria, 
where Metchnikoff found people to live to an unusually 
old age. Investigation proved to him that the regular 
indulgence in a drink, Yogart, containing this bacillus, 
was largely responsible for the good health and longevity 
of Bulgarians. Metchnikoff demonstrated that the Bul- 
garian and other lactic acid bacteria are antagonistic to 
putrefactive and allied organisms and that, by virtue 
of this, when taken into the system, will check putre- 
faction in the intestines and thus prevent the formation 
147 
