126 PROTEIN POISONS 



and no acceleration; indeed, the rate seems to be somewhat 

 slower than normal. Gradually the beat becomes more 

 and more feeble, the rate and regularity being preserved 

 to the end. It is usually only after an interval of from 

 three to four minutes after the cessation of respiration that 

 the heart ceases to beat. As has been previously stated, a 

 fatal issue, if it occurs at all, always results within one 

 hour after injection and usually within from thirty to forty 

 minutes. This is to a large extent independent of whether 

 the dose is the minimum lethal one or two or three times 

 that amount. It is certainly entirely independent of the 

 size of the pig. Death, of course, results at slightly different 

 times with different batches of the poison, but even in this 

 case the interval of time between injection and a fatal 

 issue does not vary to any great extent. A dose which has 

 proved to be the minimum fatal dose for one pig will almost 

 surely prove to be the same for another. In other words, 

 we have done away practically entirely with the period of 

 incubation, and the poison acts so rapidly that individual 

 resistance plays no part; hence, the animal acts almost 

 with the exactitude of a chemical compound into which 

 for all practical purposes it has been converted. The period 

 of incubation has ceased to exist since the poison is no longer 

 contained within either the dead or the living bacillus, but 

 is present in a free and uncombined form, capable of uniting 

 immediately with those body cells for which it may possess 

 a special affinity. 



At autopsy no special gross lesions can be made out. 

 The peritoneum is smooth and shiny throughout, and there 

 is not the slightest evidence of either hemorrhage or even 

 marked congestion in the omentum or mesentery. This is 

 very important and in marked contrast to the hemorrhagic 

 peritonitis found after injection of either the living or the 

 dead colon bacillus. We are inclined to believe that it is 

 the distinguishing feature between the injection of the 

 poison in a comparatively free and in a combined state. 

 At one time we attempted to obtain the poison by a simpler 

 method, omitting the extraction of the crude substance 



