208 VAUGHAN— THE PROTEIN POISON. [April 19, 



body. In the second stage the animal Hes in a lethargic condition, 

 with rapid, difficult respiration. It prefers not to move, and when 

 ■ urged to do so it shows that it has partially lost the power of 

 coordinating its movements. It drags its posterior extremities, or 

 it sways from side to side. This is known as the paralytic stage. 

 The third stage manifests itself by clonic covulsions, which repeat 

 themselves after intervals of rest, becoming more and more violent, 

 until death results. After reaching the convulsive stage recovery is 

 rare, although it does occasionally occur. The symptoms are pro- 

 duced by the injection of protein poison, whether obtained from 

 bacterial, animal or vegetable proteins. It should be stated that in 

 order to study these symptoms properly the dose should approach 

 the minimum quantity. When the dose is excessive the first and 

 even the second stage may not be observed. The animal is speedily 

 thrown into a convulsion, and death results within a few minutes. 

 When a non- fatal dose is given the first and second stages appear, 

 and may last in guinea pigs for an hour, possibly two, but recovery 

 is rapid and apparently complete. It is of importance to note this 

 fact, that when recovery does take place it follows rapidly, and 

 apparently the animal is as well as ever within two or three hours, 

 and possibly earlier. 



We had studied this protein poison and its effects upon animals 

 when the phenomenon of protein sensitization, improperly called 

 anaphylaxis, was discovered. All will understand that protein sensi- 

 tization is demonstrated by injecting a protein, any protein, into an 

 animal and waiting for a certain length of time, or until the animal 

 becomes sensitized, when a second injection into the same animal 

 causes the symptoms which I have described, in the same order as 

 observed when the protein poison is administered, and that the final 

 effects are the same. Comparing the phenomena of protein sensiti- 

 zation with those of protein poisoning Wheeler and I in 1907 offered 

 the following explanation of protein sensitization : When a foreign 

 protein is injected into an animal it must be disposed of in some 

 way. Unless introduced in large amount it is not eliminated by the 

 kidney. It soon disappears from the circulating blood and is de- 

 posited in various tissues, the exact place of deposition depending 



