THE PARENTERAL INTRODUCTION OF PROTEINS 359 



The only pig that gave any evidence of sensitization was 

 the one that had received the first blood, drawn one hour 

 after the injection of the egg-white. The symptoms in 

 this animal were slight and transitory. The other pigs 

 showed no indications of having been sensitized. It seems 

 from this that after one hour there was no egg-white in the 

 circulating blood of the rabbit. All of these pigs had been 

 sensitized to the proteins of the rabbit's blood as was shown 

 by treating them with rabbit serum. 



January 4, 1910, the guinea-pigs that had received the 

 extracts of the organs were treated with the egg-white 

 dilution. All were affected within a few minutes. 



The one that had received the kidney extract was most 

 seriously disturbed and passed to the convulsive stage, but 

 ultimately recovered. The one that had the spleen extract 

 came next in the severity of the symptoms developed. The 

 first and second stages were well-marked in this animal, 

 somewhat less so in the pig that had received the extract 

 from the brain. Much to our surprise, the pig that had 

 received the extract from the liver was least affected. 

 However, failure to sensitize with the extract from an 

 organ does not necessarily mean that the tissue of the organ 

 contained none of the foreign protein. It may combine 

 with certain tissues so firmly that it is not removed by a 

 simple solvent, like physiological salt solution. The fact 

 that from certain organs the extracts did sensitize the pigs 

 shows that these tissues had absorbed the egg-white, but 

 failure to sensitize or to sensitize so fully with other extracts 

 does not conclusively show that such tissues have not 

 absorbed the protein. 



8. Egg-white carried into the tissue after intravenous 

 injection may be washed back into the blood current by 

 transfusion with salt solution. 



A rabbit received intravenously 50 c.c. of the egg-white 

 dilution. After one hour egg-white had disappeared 

 from the circulating blood. Two and one-half hours after 

 the injection of the egg-white, the animal was transfused 

 with physiological salt solution. During the transfusion, 



