Milk and its Ferments. 13S 



In all of the so-called natural or spontaneous fermentations this 

 fact has a most important bearing. The ferment which is able 

 to develop first and take possession of a liquid, is naturally 

 the one which, by suppressing the others, is able first to exercise 

 its function, and bring about the change called fermentation. 



Having dealt with the conditions which control ferments in 

 their development, the lecturer said : — Our next consideration 

 is where the organisms come from, and how they get into the 

 milk. We have every reason to believe that milk as secreted 

 by a healthy animal is quite sterile. Pasteur has shown that 

 other animal secretion fluids are biologically pure ; that is, if 

 they can be collected without contamination from the organisms 

 that float in the air, they will keep without change for an 

 indefinite time. I have satisfied myself that milk can be kept 

 without sterilising ; — in other words, that it contains no ferment 

 spore until exposed to the air, which is full of them. If we 

 consider the comparative food value of fermented against fresh 

 or unfermented milk, it may at once be fairly assumed that the 

 former is far greater, as the difficulty of digestion has already 

 been partially overcome by supplying part of the nutritious 

 properties of the milk in a directly assimilable condition. I 

 have had much experience of the stimulating effect of such food 

 on the yeast plant, and I may add, that in several individual 

 cases of alimentary difficulty, the direct benefit which may 

 result from the use of fermented milk as a food has come under 

 my own observation. 



Of late years we have heard a great deal about fermented 

 milk drinks that have been introduced to us from Eastern 

 Europe, and much has been written on their use as an article 

 of diet. A number of foreign observers have from time to time 

 during the last fifty years published books or papers on a 

 Caucasian fermented milk drink called " koumiss," which is 

 prepared from mare's milk, and is recommended by many 

 members of the medical profession in the treatment of wasting 

 lung diseases or alimentary complaints. Genuine " koumiss " 

 is made from mare's milk by the wandering Tartar tribes of the 



