124 BACTERIAL POISONS. 



Diphtheria. — That the Loffler bacillus is a cause 

 of diphtheria no one can now deny. The fact that this 

 germ, although found only at the seat of inoculation, causes 

 marked systemic disturbances, indicates that its action must 

 be due to its soluble products. This was early recognized 

 by Loffler, who in 1887 attempted to ascertain the 

 nature of the poison. A flask of bouillon containing pep- 

 tone and grape-sugar was, three days after it had been 

 inoculated with the bacillus, evaporated to 10 c.c, and this 

 was injected into an animal, but was without effect. A 

 second flask of the same material was extracted with ether, 

 but this extract was also found to be inert. Next, some 

 neutral beef broth was extracted with glycerin some four 

 or five days after it had been inoculated with the bacillus. 

 The glycerin extract, when treated with five times its 

 volume of absolute alcohol, deposited a voluminous, floc- 

 culent precipitate, which was collected, washed with alcohol, 

 dried, and dissolved in a little water. A further precipita- 

 tion with alcohol and a current of carbonic acid gas secured 

 a white substance, and the injection of from 0.1 to 0.2 

 gramme of this, dissolved in water, subcutaneously in 

 guinea-pigs, caused marked pain followed by a fibrous 

 swelling with hemorrhage into the muscles and oedema, 

 terminating in necrosis. From these studies Loffler 

 concluded that the poison belongs to the enzymes. 



Roux and Yersin found that bouillon cultures from 

 which the bacillus had been removed by filtration through 

 a Chamberland filter are poisonous, especially cultures 

 which are four or five weeks old. The results obtained 

 varied with the amount of the fluid, the species of animal, 

 and the method of administration. The effects observed 

 were a serous exudation into the pleural cavity, a marked, 

 acute inflammation of the kidney, fatty degeneration of the 

 liver, especially after injection into a bloodvessel, and cede- 

 matous swelling in the surrounding tissue after subcu- 

 taneous inoculation. In some instances, in dogs, rabbits, 

 and guinea-pigs, paralysis, generally in the posterior extre- 

 mities, followed. The action of the poison was found to 

 be very slow, and, as a rule, death occurred days, and in 



