376 BACTERIOLOGY. 



form and thymol, and by drying, without apparently 

 any alteration of this poisonous body. Absolute alco- 

 hol, concentrated solutions of neutral salts, and a tem- 

 perature of 100 C., decompose this substance, leaving 

 behind secondary poisons which possess a similar physi- 

 ological activity, but only when given in from ten to 

 twenty times the dose necessary to produce the same 

 effects with the primary poison. 



Other members of the vibrio family also, namely, 

 vibrio Metchnikovi and that of Finkler and Prior (see 

 description of these species), contain, according to Pfeif- 

 fer, closely related poisons. 



Experiments upon animals. As a result of experi- 

 ments for the purpose of determining if the disease can 

 be produced in any of the lower animals it is found 

 that white mice, monkeys, cats, dogs, poultry, and many 

 other animals are not susceptible to infection by the 

 methods usually employed in inoculation experiments. 

 When animals are fed on pure cultures of the comma 

 bacillus no effect is produced, and the organisms cannot 

 be obtained from the stomach or intestines; they are 

 destroyed in the stomach and do not reach the intes- 

 tines; they are not demonstrable in the feces of these 

 animals. Intravascular injections of pure culture into 

 rabbits are followed by a temporary illness, from which 

 the animals usually recover in from two to three days; 

 intraperitoneal injections into white mice are, as a rule, 

 followed by death in from twenty-four to forty-eight 

 hours; the conditions in both instances most probably 

 resulting from the toxic activities of the poisonous pro- 

 ducts of growth of the organisms that are present in the 

 culture employed. None of the lower animals have ever 

 been known to suffer from Asiatic cholera spontaneously. 



