70 BACTERIAL POISONS OF INFECTIOUS DISEASES. 



it inert. In the majority of the experiments the filtration method 

 was used, and in this way a large quantity of a poisonous fluid of 

 uniform strength was obtained. Varying amounts of this fluid were 

 used upon animals, mostly guinea-pigs and rabbits, and it was found 

 that the eflects depended upon the quantities employed and the 

 methods of administration. In all cases in which death did not oc- 

 cur too early, paralysis appeared. The limbs were first paralyzed, 

 and this was true whether the fluid was administered intravenously 

 or subcutaneously. The post-mortem appearances were identical 

 with those observed after inoculation with the bacillus, with the ex- 

 ception of the absence of the pseudo-membrane. After subcutaneous 

 injection there was a gelatinous, grayish-white, sometimes reddish, 

 cedematous fluid, formed at the point of injection, and, after large 

 doses, necrosis. In cases in which death was delayed, there were 

 eflusions in the pleura, fatty degeneration of the liver, and inflam- 

 mation of the kidneys. 



Brieger and Frankel conclude this part of their report with the 

 following statement : " We have shown that the Loef&er diphtheria 

 bacillus produces in its cultures a poisonous, soluble substance, sep- 

 arable from the bacteria, which causes in susceptible animals the 

 same phenomena induced by inoculation with the living micro-organ- 

 ism. We have further shown that this substance is destroyed by a 

 temperature over 60°, but that it can be heated to 50°, even in the 

 presence of an excess of hydrochloric acid, without being destroyed. 

 This kst fact is contrary to the assumption that the chemical poison 

 of the diphtheria bacillus is a ferment or an enzyme." 



The filtered cultures were tested for basic products, but with neg- 

 ative results, excepting that small amounts of creatinin and cholin 

 were found. They were also distilled at from 20° to 35° in a vacuum, 

 but the distillate was found to be inert. The toxin is soluble in 

 water, insoluble in alcohol, and non-dialyzable. It is precipitated 

 by saturation with ammonium sulphate. As a result of their first 

 work on this subject, Brieger and Frankel concluded that the diph- 

 theria toxin is a toxalbumin ; however, they, as well as others, have 

 since learned that while the body obtained by them contained the 

 toxin, the bulk of it was made up of other substances. 



Tangl has shown experimentally that the toxin is formed in the 

 body as well as in culture flasks. A large piece of pseudo-membrane 

 was macerated in an ice-chest in water for twenty-four hours, and 

 then filtered through porcelain. The filtrate, injected into animals, 

 produced all the symptoms that had been obtained by similar em- 

 ployment of artificial cultures. The same observer found that in 

 some cases in which the animals were inoculated with the sterilized 

 culture through the mucous membrane a pseudomembrane formed at 

 the point of injection. Diphtheria toxin has also been found in the 

 tissues, blood, and urine. 



