408 PROTEIN POISONS 



group, and consequently the subnormal as well as the high 

 temperature is a result of parenteral digestion, and it is 

 in this stage that the greater danger to the life of the animal 

 lies, as is plainly shown in our results. However, there is 

 danger to life in the high temperature in and of itself. A 

 rabbit is not likely to survive a temperature above 107, 

 and this was reached in at least one of our experiments, and 

 closely approached in many others. 



Fever must be regarded as a conservative process, although 

 like many of nature's processes it often leads to disaster. 

 But its purpose is the disposal of foreign and dangerous 

 material, and therefore must be regarded as beneficent. 



In parenteral digestion the following sources of heat 

 production must be evident: (1) The unaccustomed 

 stimulation and consequent increased activity of the cells 

 which supply the enzymes must be the source of no incon- 

 siderable increase in heat production. (2) The cleavage of 

 the foreign protein means the liberation of heat. (3) The 

 reaction between the products of the digestion and the 

 tissues, especially when an active and irritant poison is 

 liberated, must lead to increased heat production. \Ve 

 regard the first and last of these as the more important 

 sources of the overproduction of heat in the febrile state. 



Special Conclusions. 1. Large doses of unbroken protein 

 administered intra-abdominally, subcutaneously, or intra- 

 venously have no effect upon the temperature; at least, 

 do not cause fever. 



2. Small doses, especially when repeated, cause fever, 

 the forms of which may be varied at will by changing the 

 size and the interval of dosage. 



3. The effect of protein injections on the temperature is 

 more prompt and marked in sensitized than in fresh animals. 



4. The intravenous injection of laked blood corpuscles 

 from either man or the rabbit causes in the latter even in 

 very small quantity, either in single or repeated doses, 

 prompt and marked elevation of temperature. 



5. Laked corpuscles after removal of the stroma by 

 filtration have a like effect. 



