THE NATURE OF TOXIN 



117 



Guinea-pigs injected with colloid 3a 



22 

 23 



2.0 

 2.0 



Died second day; typical lesions 

 Died third day; typical lesions 



Guinea-pigs injected with colloid 4 



Guinea-pigs injected with colloid 5 



28 

 29 

 30 

 31 



2.0 

 2.0 

 2.0 

 2.0 



Died third day; typical lesions 

 Died first day; typical lesions 

 Died fifth day; fair lesions 

 Died tenth day; typical lesions 



made intraperitoneally into guinea-pigs of 250 grams average 

 weight. The autopsies showed the characteristic lesions. All 

 the colloidal fluids were matured for one and one-half hours at 

 20°C. 



The neutralizing action of antitoxin upon artificial toxin is 

 indicated in the foregoing table. The dose of toxin used was one 

 always fatal to guinea-pigs in six to eight hours. It would have 

 occasioned no surprise had antitoxin failed to protect, since at 

 best we had only hoped to approximate the toxic colloid in our 

 artificial mxtures, but the experiments while they have not been 



