is one of the first, most definite and most reassuring signs of improvement in the clinical condition of certain kinds of patients) to make use of any mode of lactic acid bacillus therapy which will inhibit the normal development of B. lactis ærogenes or B. coli communis in the digestive tract would, in my judgment, be a profound error in principle. I do not wish to intimate that I consider B. bulgaricus or any of the common lactic acid bacilli to be capable of seriously checking the growth of B. lactis ærogenes and B. coli communis in the digestive tract, but wish to state that in so far as such modification is possible it appears to me not without undesirable features. To the validity of this statement there is one possible exception that occurs to me. In cases where there is a colon bacillus infection of the intestine, that is to say, an inflammatory state associated with a great over-growth of B. coli, the antagonistic influence of lactic acid bacilli might be useful. But I am not sure that this is more than a merely apparent exception to the general rule which I have above expressed as valid, for it is not clear that it has been proved that the colon bacilli apparently answerable for digestive infections are in reality the normal colon bacilli. It appears to me more likely that they are commonly variants of such bacilli whose fermentative characters have not yet been determined fully and precisely.
I would also mention here the fact that there are diseases of the intestinal tract associated with the presence of bacteria capable of forming lactic acid. Obviously, then, this property of a microorganism does not necessarily screen the digestive tract from injury.
One of the most important and most loudly heralded effects of the administration of soured milk is that on intestinal putrefaction. Under conditions of health the putrefactive decompositions in the intestinal tract seldom attain a considerable degree of intensity—a surprising fact when we consider the immense numbers of bacteria which inhabit the large intestine. In many pathological states the conditions of putrefaction in the intestine are very much altered in the direction of great intensification. This is shown both by the dominance of putrefactive microorganisms in the large intestine and by the appearance of products of putrefaction in the urine. It is unnecessary here to discuss the nature of these products. It should, however, be pointed out that the intensity of putrefaction as judged by the quantity of putrefactive products in the urine is notably influenced by the quantity of protein material ingested. We may say that in general a considerable increase in the protein intake is followed by a corresponding increase in putrefaction and that a marked diminution in protein intake is followed by a distinct falling off in putrefaction. This statement holds true in general in conditions of health and it is even more strikingly exemplified in cases of chronic intestinal infection associated
