( 33 ) 



as in the ease described before in quite an interior number. This 

 fact acquires a special significance when we consider that Escherigh, 

 the discoverer of the colibacillus, has proved that this condition exists 

 directly behind the baby's stomach, where coli and aërogenes are 

 predominant which, in reference to the preceding, necessitates the 

 conclusion that even at those portions of the intestines where a 

 lactic acid flora should first lie looked for, it is evidently unable to 

 sustain itself. 



There is no doubt but here too, the strongly disinfecting action 

 of the stomachal hydrochloric acid plays a part, as this acid, at a 

 much lower titer than the lactic acid checks the growth of the lactic 

 acid ferments, but hence can be neutralised by much less alcali, 

 which is not indifferent to coli, which produces alcali. 



In so far as the theory of Metchnikoff and Combe is right, after 

 which yoghurt or other sour milk preparations counteract the auto- 

 intoxication from the intestinal canal, it seems certain that here 

 should more be thought of the influence of a milk diet and the free 

 acid taken up with the milk, than of a specific intestinal tlora. But 

 in how far the apparently proved decrease of indol and phenol, 

 whose quantity is considered as determining the degree of auto- 

 intoxication, deviates, at a nutrition with soured milk preparations 

 instead of meat, from this decrease when non-soured milk is used, 

 — to my opinion the real core of the question, — has not been 

 considered by the said authors. 



Admitting that the soured preparations really deserve to be 

 preferred, I think that especially in Holland, it must be possible 

 with good buttermilk in as simple a way to reach the wished for 

 end, as with the various exotic ferments, whose descriptions give 

 the impression that the preparator» are but imperfectly acquainted 

 with the general phenomena of the lactic acid fermentation in milk. 



Although J see no fundamental difference between the use of 

 buttermilk and yoghurt, it is certain that the latter may be prepared 

 in a very simple way under medical control, and hence, to my 

 meaning, deserves to be recommended in certain cases. 



Summarising the preceding I come to the following conclusion. 



In milk three chief forms of lactic acid fermentation, determined 

 by temperature, are to be distinguished, namely at very low tempe- 

 rature, the slimy lactic acid fermentation ; at a middle temperature 

 the common lactic acid fermentation caused by Lactococcus ; and at 

 higher temperature the lactic acid fermentation by Lactobacillus. 



The elective culture of the microbes of the slimy fermentation, 

 succeeds by cultivating baker's yeast in absence of air between 15° 



3 



Proceedings Royal Acad. Amsterdam. Vol. X. 



