FERMENTED MILK 481 



tities sufficient to cause the symptoms of autointoxication; 

 (2) the putrefaction or fermentation through which these 

 toxic substances are produced can be suppressed by other 

 bacteria; and (3) the bacteria which it is proposed to use in 

 suppressing the putrefactive bacteria may be introduced into 

 the intestines and will be able to establish conditions there 

 under which they will multiply and persist, while the objec- 

 tionable types are driven out. 



The standing of the theory of autointoxication mentioned 

 under the first condition cannot be discussed in detail in a 

 book of this nature. It maybe said, however, that the question 

 of autointoxication, in its broader sense/is not nearly so simple 

 as it is stated here. It is at best only a theory, and much in- 

 vestigation of details will be necessary before its position can 

 be determined. 



The second condition is easily demonstrated, not only by 

 scientific observations, but also by many instances in our daily 

 life. Vinegar, which is used in pickle-making, owes its preserva- 

 tive action to the acetic acid produced by a bacterial fermen- 

 tation ; when milk sours spontaneously, the acid-forming bac- 

 teria develop acid so rapidly that in a short time all other 

 bacteria are inhibited. Observations of this kind could be 

 multiplied almost indefinitely. In fact, in the bacterial 

 world, as among the higher plants in their natural state, there is 

 a constant struggle for mastery in which the types best suited 

 to their environments, or, perhaps more correctly, less sensi- 

 tive to the unfavorable conditions which they themselves 

 produce, gain the ascendency and more or less completely 

 suppress other forms. 



The particular bacterium which it is proposed to use in sup- 

 pressing the putrefactive bacteria of the intestines is the organ- 

 ism commonly known as Bacillus bulgaricus, or the MetchnikofT 

 bacillus. It is characterized by its ability to form acid in ex- 

 ceptionally large amounts from sugars, particularly milk-sugar. 

 2i 



