OLD AGE. 547 



When taken in \(n-y larji'e quantities, perish in the intestines of man 

 and of animals. Thus, for exami)le, the vil)ri() of cholera, tliat dread 

 agent of Asiatic cholera, has many times been swallowed with im- 

 punity by various j^ersons. Its destruction was so complete that it 

 was impossible to find it again in the alimentary waste. Schiitz 

 introduced directly into the small intestine of dogs a quantity of 

 vibrios which he saw soon after had disappeared. The same phenom- 

 ena were observed in chickens, the microbes being destroyed in their 

 digestive tubes. 



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

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

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

 been established by experiment. In curdled milk prej^ared by a fer- 

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

 at Geneva, there is found a large bacillus remarkable for its ability 

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

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

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

 alive. Its presence has been demonstratcMl by Doctor Cohendy even 

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

 microbe not normally present in our intestinal flora Avhich may be 

 implanted there artificially, either with curdled milk or under the 

 form of a pure culture; endowed with great power of producing 

 fermentation, it Avill be capable of effectively combatting intestinal 

 putrefactions. 



It is interesting to note that this microbe is found in the sour milk 

 consumed in large quantities by the Bulgarians in a region famous 

 for the longevity of its inhabitants. 



We have, then, reason to suppose that the introducticm 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 nucrobes 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 })ossil)le, uncooked 

 foods that serve as x'ehicles for all sorts of microlu's. In spite 

 of the washing of vegetalffes and fruits, such as salads, radishes, 

 strawberries, 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 sAvallowed. 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 



