136 Milk and its Ferments. 



plains of South-Eastern Russia. " Kephir " is made from 

 cows' or goats' milk by the Tartar people who live on the hills 

 and mountains. Both these fermented milks are strictly 

 articles of diet. " Kephir " especially is for long periods of the 

 year the exclusive diet of the wandering hill tribes, who at high 

 altitudes far away from their settlement have no means of 

 obtaining much other food. The origin and peculiar properties 

 of both these Caucasian milk drinks are solely due to situation 

 and climatic surroundings. It would be impossible to make the 

 same fermented milk even under fairly similar conditions in 

 this country. The best we can do is to imitate as nearly as 

 possible. It is impossible, or at least very difficult, to make a 

 good imitation of koumiss from cow's milk. Any home 

 preparations that I have tested were very different to that made 

 from mare's milk. The ferment organisms of " kephir " consist 

 of a small special type of yeast, and a lactic bacillus which has 

 been named by E. Kern, of Moscow, "Dispora Caucasica ;" but 

 I think that in giving it the name Kern has been deceived, like 

 many another investigator of lactic ferments, The number of 

 ferment organisms which develop to bring about these changes 

 in "kephir," or in ordinary buttermilk, might be easily estimated 

 by the nutrient gelatine plate process. I have found them, by 

 actual counting, to amount to nearly 5,000,000 in a single cubic 

 centimetre of the fully fermented milk, which equals about 

 30,000,003 in the measure of a small teaspoonful, and this 

 calculation certainly underestimates their actual number. In 

 conclusion, I hope you can follow me in recognising our 

 indebtedness to these tiny ferment organisms, as this example 

 only refers to one of the many duties which they are performing, 

 and which were unknown to us until revealed by recent 

 methods of biological research. 



The lecture was illustrated by special photographic slides 

 prepared by Mr. Welch and Mr. James Stelfox, and a micro- 

 scopic demonstration of some of the milk ferments and moulds 

 living in pure conditions of culture. 

 An interesting exhibition of bacilli and microbes took place, 



