42 THE POPULAR SCIENCE MONTHLY 



of such food. I have seen several instances of this error, which is not 

 confined to laymen, but is sometimes committed by physicians also. 



Another feature of fermented milk which needs to be closely scru- 

 tinized is the character of the microorganisms employed as fennents 

 of the milk. In a few instances I have known to be used as ferments 

 what I believe to be very undesirable types of bacteria. I think it 

 may be said that most of the fermented milks on the market in this 

 country at the present time contain chiefly fermentative organisms 

 which are harmless when not excessively administered. In some cases 

 the lactic-acid producing bacteria have become contaminated by pos- 

 sibly undesirable yeasts. It is only natural that accidents of this sort 

 should occur in what is comparatively a new industry, and it is likely 

 that with increasing experience the manufacturers of the various fer- 

 mented milks will be compelled to exercise every reasonable caution in 

 regard to the purity and quality of the ferments employed in their 

 products. 



The use of tablets of other preparations of lactic acid bacilli is 

 now becoming widespread. The tablets are taken with some carbohy- 

 drate material which will permit the growth of the bacteria and the 

 formation of lactic acid. I have seen good results from this method 

 of using lactic acid bacilli, in the relief of symptoms referable to ex- 

 cessive intestinal putrefaction. But I do not think the data exist at 

 present for an intelligent comparison of this use of lactic acid bacilli 

 with their use in fermented milks. I hope before long to be able 

 to discuss this question on the basis of experimental observations. 



