OLD AGE. 547 



wlion (iikcii in \('r_v ii\r<xv (luaiilit ics. pci-ish in tlic iiilostinos of inini 

 and of animals. Thus, for oxaniplo, the vibrio of cholera, that .h-cad 

 agvnt of Asiatic chohn-a, has many times been swaUowed with im- 

 punity by various persons. Its destruction was so complete that it 

 was impossible to find it a^-ain in the alimentary waste. Schiitz 

 introduced directly into the small intestine of d()o;s a (juantitv of 

 vibrios which he saw soon after luuf disai)peared. The same j)hen()m- 

 ena were observed in chickens, the microbes bein^ destroy«>d in their 

 diofestive tubes. 



In every attempt at a modification of the intestinal flora it is, then, 

 necessary to find out whether a driven microbe is really capable of 

 living in the intestines. For certain lactic microbes this fact has 

 been estal)lished by experiment. In curdled milk prepared by a fer- 

 ment of Bulgarian origin, placed at our disposal by Professor Massol, 

 at (ieneva. there is found a large bacillus remarkal)le for its ability 

 to produce a great amount of lactic acid. This bacillus, when swal- 

 loAved by man, does not suffer the fate of the vibrios which we have 

 mentioned. It is not destroyed in the intestines, but passes through 

 ali^•e. Its presence has been demonstrated by Doctor Cohendy even 

 many days after its introduction by the mouth. Here, then, is a 

 microbe not normally present in our intestinal flora which may be 

 implanted there artificially, either with curdled milk or under the 

 form of a pure culture; endowed Avith great ])ow(>r of })roducing 

 fermentation, it Avill be capable of effectively combatting intestinal 

 putrefactions. 



It is interesting to note that this microl)e is found in the soui' milk 

 consumed in large ({uantities by the Bulgarians in a region famous 

 for the longevity of its inhabitants. 



We have, then, reason to suppose that the introduction of this Bul- 

 garian clotted milk into our diet may counteract, or at least diminish, 

 the injurious effect of the intestinal flora. This would be the first 

 example of artificial modification of that flora. 



To sow useful microbes within our digestive tube is not sufficient. 

 It is also necessary to prevent the introduction of injurious ones. 

 With this end in view we should avoid, as much as possible, uncooked 

 foods that serve as vehicles for all sorts of microbes. In spite 

 of the w^ashing of vegetables and fruits, such as salads, radishes, 

 trawberries, cherries, and others, they are yet contaminated with 

 dust, soil, manure, and fecal matters. Now, these often contain in- 

 jurious microbes and eggs of animal parasites. Doctor Bienstock 

 found in the earth of his strawberry beds tetanic spores, which he 

 found would be destroyed in his own digestive tube when a little of 

 that earth was swallowed. But we must not count too much on the 

 antimicrobic power of our intestines, and it is much more prudent not 

 to. use these vegetables and fruits until they are cooked — that is to 



