186 EELATIONS OF BACTERIA TO DISEASE 



processes predominate, fever is rarely absent, and it is nearly 

 always present when there is an active leucocytosis going on. 

 In this connection it may be remarked that several observers 

 have found that, when a relatively small amount of the dead 

 bodies of certain bacteria are injected into an animal, fever 

 occurs ; while the injection of a large amount of the same is 

 followed by subnormal temperatures and rapidly fatal collapse. 

 It might appear as if this indicated that the occurrence of fever 

 had a beneficial effect, but this is one of the points at issue. 

 Certainly such an effect is not due to the bacteria being unable 

 to multiply at the higher degrees of temperature occurring 

 in fever, for this has been shown not to be the case. Whether 

 the increase of bodily temperature indicates the occurrence of 

 changes resulting in the production of bactericidal bodies, etc., 

 is very doubtful ; a production of antagonistic substances may 

 be effected without the occurrence of fever or of any apparent 

 disturbance of health. If we consider the site of the heat 

 production in fever we again are in difficulties. It might appear 

 as if the tissue destruction, indicated by the occurrence of fatty 

 degeneration, would lead to heat development, but frequently 

 excessive heat production with increased proteid metabolism 

 occurs without any discoverable changes in the tissues ; and 

 further, in phosphorus poisoning there is little fever with great 

 tissue destruction. The increased work performed by the heart 

 in most bacterial infections no doubt contributes to the rise of 

 bodily temperature. But we must bear in mind that in fever 

 there is more than mere increase of heat production there is 

 also a diminished loss of heat from interference with the nervous 

 mechanism of the sweat apparatus. The known facts would 

 indicate that in fever there is a factor involving the nervous 

 system to be taken into account. The whole subject is thus 

 very obscure. 



Symptoms. Many of the symptoms occurring in bacterial 

 infections are produced by the histological changes mentioned, 

 as can be readily understood ; whilst in the case of others, corre- 

 sponding changes have not yet been discovered. Of the latter 

 those associated with fever, with its disturbances of metabolism 

 and manifold affections of the various systems, are the most 

 important. The nervous system is especially liable to be 

 affected convulsions, spasms, coma, paralysis, etc., being 

 common. The symptoms due to disturbance or abolition of the 

 functions of secretory glands also constitute an important group, 

 forming, as they do, a striking analogy to what is found in the 

 action of various drugs. 



