CONTROL OF BODY TEMPERATURE AND FEVER 753 



and heat puncture, lends support to the view that in its initial stages 

 experimental fever of this type is the result of an excessive breakdown 

 of glycogen in the liver. It must not be imagined, however, that persist- 

 ent fever can be attributed to such a cause, since the fever remains after 

 the glycogen has all been removed. Other chemical substances produc- 

 ing fever are caffeine, certain other purines, and particularly tetra-hydro- 

 naphthylamin. 



Belonging to this group of fevers must also be considered the im- 

 portant ones produced by the intravenous injection of certain forms of 

 protein, as those of egg white or those derived from the bodies of bac- 

 teria or from the laked corpuscles of a foreign blood. The fever in 

 these cases is no doubt caused by a mechanism, closely related to that 

 responsible for anaphylaxis (see page 90). Such injections do not pro- 

 duce fever in animals after division of the cervical spinal cord or ex- 

 cision of the midbrain. It is believed that many cases of so-called asep- 

 tic fever, occurring after severe contusions or other wounds, may be 

 the result of destruction of proteins within the body. Similarly the rise 

 in temperature during infections may be owing to the breakdown of pro- 

 tein by microorganisms within the cells. 



Significance of Fever in the Organism 



It is impossible at present to state definitely whether fever is a re- 

 action of the organism against some infection and therefore of benefit 

 in assisting the organism to combat it, or whether it is in itself an un- 

 favorable condition. . The question can certainly not be answered by 

 observing the behavior of bacteria growing at different temperatures 

 in various media outside the body. That certain bacteria should be 

 found not to thrive at incubator temperatures equal to those found in 

 the body during fever, does not at all prove that this fever is of sig- 

 nificance as a means of combating the growth of the bacteria in the 

 body. It is undoubted that, where the body temperature becomes ex- 

 cessively high, the correct treatment is to keep it down as much as 

 possible. On the other hand, the reduced mortality that has followed 

 the introduction of the cold-bath treatment in typhoid fever may not 

 be due so much to the reduction in body temperature itself as to 

 the favorable effect produced on the nervous system and circulation. 

 We certainly know that in normal animals moderate degrees of hyper- 

 pyrexia produced by exposure to moist heat are well borne for consider- 

 able periods of time, thus indicating that it is the infection and not the 

 hyperthermia that causes the serious damage to the body in infectious 

 fevers. 



