Page:Popular Science Monthly Volume 74.djvu/46

42 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 scrutinized is the character of the microorganisms employed as ferments 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 possibly 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 fermented 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 carbohydrate 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 excessive 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.