THE TOXINS PRODUCED BY BACTERIA 161 



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 

 affections 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. 



These tissue changes and symptoms are given only as illus- 

 trative examples, and the list might easily be greatly amplified. 

 The important fact, however, is that nearly all, if not quite all, 

 the changes found throughout the organs (without the actual 

 presence of bacteria), and also the symptoms occurring in infective 

 diseases, can either be experimentally reproduced by the injection 

 of bacterial poisons or have an analogy in the action of drugs. 



THE TOXINS PRODUCED BY BACTERIA. 



Early Work on Toxins. We know that bacteria are capable 

 of giving rise to poisonous bodies within the animal body and 

 also in artificial media. We know, however, comparatively little 

 of the actual nature of such bodies, and therefore we apply to 

 them as a class the general term toxins. The necessity for 

 accounting for the general pathogenic effects of certain bacteria, 

 which in the corresponding diseases were not distributed 

 throughout the body, directed attention to the probable exist- 

 ence of such toxins ; and the first to systematically study the 

 production of such poisonous bodies was Brieger. This observer 

 isolated from putrefying substances, and also from bacterial 

 cultures, nitrogen-containing bodies, which he called ptomaines. 

 Similar bodies occurring in the ordinary metabolic processes of 

 the body had previously been described and called leucomaines. 

 Ptomaines isolated from pathogenic bacteria in no case repro- 

 duced the symptoms of the disease, except perhaps in tetanus 

 and this only owing to their impurity. The methods by 

 which they were isolated were faulty, and they have therefore 

 only a historic interest. 

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