CHOLERA. VIRUS. 149 



gave no further details as to the preparation of his poison, but 

 BEHRiNG 1 subsequently stated that Ransom's poison was obtained 

 from cultivations of five to ten days' growth, by means of a short 

 heating at 100 C., filtration through a Pukall's filter, and pre- 

 cipitation with alcohol. 



This solid poison is stated to produce violent choleraic symp- 

 toms and death when tried upon animals. It causes in the 

 organism of the animal a slight formation of antitoxine (protec- 

 tion against four to six times the lethal dose), and in this respect 

 should be regarded as a true toxine. Against this, however, 

 must be placed its stability when heated, which, according to 

 RANSOM, is one of its characteristics, and also its relatively 

 small toxic action (0-07 grm. of the solid poison is the lethal 

 dose for guinea-pigs). PFEIFFER, therefore, regards Ransom's 

 poison as a secondary product, and is of opinion that its 

 reputed antitoxic power is not greater than that of the normal 

 serum. 



METSCHNIKOFF, Roux, and TAURELLI-SALIMBENI 2 brought 

 forward the following interesting experiments in opposition to 

 Pfeiffer's theory : They placed 3 to 4 c.c. of a peptone solution, 

 part of which contained living vibriones and in part of which 

 the micro-organisms had been killed by means of chloroform, in 

 sterilised collodion capsules, which were then hermetically closed 

 and placed in the abdominal cavity of guinea-pigs. The animal 

 treated in this way with the dead vibriones became slightly ill, 

 whereas that poisoned with the living micro-organisms perished 

 in three to five days with typical choleraic symptoms. Post- 

 mortem section showed the usual alterations found in cholera, 

 but in none of the organs were there any vibriones, although 

 these were alive in the capsule. 



Some of the animals survived and then showed an increased 

 resistance. 



The inevitable deduction to be drawn from this experiment is 

 as follows : 



In the culture medium contained in this closed capsule which 

 thus represented a model intestine, there was formed a poison 

 which could diffuse through the collodion membrane whilst the 

 vibriones developed vigorously inside the capsule. On the other 

 hand, but little poison was liberated from the dead cells only 

 sufficient to produce slight illness. 



1 Behring, ' ' Untersuch. Ransoms iib. die Agglutination der Cholera- 

 vibriones," Deutsch. med. Woch., 1898, 294. 



2 Metschnikoff, Roux, and Taurelli-Salimbeni, ' ' Toxine et antitoxine 

 cholerique," Ann. Past., x., 257, 1896. 



