TOXINES. 23 



The specific nature of true toxines completely corresponds with 

 that of the living bacteria. 



It is also characteristic of most of the known toxines that, 

 unlike most simple crystalloid poisons, they do not exert their 

 activity instantaneously or after a very short time, but that their 

 toxic effects only appear after a definite time the period of 

 incubation. In this respect, too, bacterial toxines behave exactly 

 like their parent living cells. The period of incubation varies, 

 not only with the nature of the toxine, but is also dependent 

 on other factors, such as the amount of the dose, the body tem- 

 perature, &c. There is a limit, however, to this dependency, 

 particularly as regards the amount of dose. The period of in- 

 cubation is not in any way inversely proportional to the quantity 

 of toxine. For example, according to COURMONT and DoYON, 1 

 the period of incubation for guinea-pigs after injection of a lethal 

 dose of diphtheria toxine is fifteen hours, and this cannot be 

 reduced below twelve hours even by the introduction of enormous 

 doses (90,000 times the lethal amount). A very interesting 

 phenomenon in connection with this point is that in tetanus of 

 the frog the incubation period can be delayed to any desired 

 extent, by keeping the temperature low. Thus, if a frog into 

 which the poison has been injected be kept at 8 to 10 C., it 

 remains healthy, but at 30 C. tetanus begins after a definite 

 time, and the frog dies. If, again, the warming be interrupted, 

 the frog can be kept at 8 C. as long as desired, but after com- 

 pletion of the remainder of the incubation period at a higher 

 temperature, tetanus symptoms appear (MORGENROTH). 



In the case of some other toxines, however, notably snake 

 venom, there is not this incubation period. These act with 

 extreme rapidity. 



KRAUS 2 found a true antitoxine-producing toxine in the filtrates of 

 cultivations of Naskin's vibrio, which resembles the cholera vibrio. It 

 killed rabbits without an incubation period when intravenously injected in 

 doses of 0'5 to 1 c.c. There was an incubation period after subcutaneous 

 injection. 



Constitution of Toxines. The characteristic of every toxine is 

 that it is a haptine in other words, that it contains a haptophore 

 and a toxophore group. 



Taking their constitution as thus fixed, most bacterial toxines 



1 Quoted by Deutsch and Feistmantel, Die Impfstqffe und Sera, Leipzig, 

 1903, 40. 



2 Kraus, " Ueb. ein acut. Wirkendes Bakterientoxin," Centralbl. /, 

 Bakt., xxxiv., 488, 1904. 



