ACTION OF TOXINS 409 



substances which have a peculiar affinity for certain tissues of the 

 body on which they produce their special toxic eifect. Hitherto, all 

 attempts at the separation of such bacterial ferments have been 

 without success, and for other reasons also the whole question of 

 such ferments must be left open at present. Sidney Martin and 

 others have demonstrated that many of the extra-cellular toxins are 

 albumoses or bodies of a similar nature. They are non-crystallisable, 

 soluble in water, precipitated along with the proteids by concentrated 

 alcohol, relatively unstable, having their toxicity diminished or 

 destroyed by heat, light, or certain chemical agents. As for the 

 products of digestion, they are formed either by the bacillus ingest- 

 ing the proteid and discharging it as-albumose, or the digestion 

 occurs by means of a ferment secreted by the bacillus in the body of 

 the individual or animal suffering from the disease. 



It is now held by some that the virus of anthrax produces 

 albumoses and an alkaloidal substance (Martin), the former producing 

 fever, the latter oedema, congestion, and local irritation. Hankin 

 arrived at the view that the bacillus first produces a ferment and 

 then elaborates albumoses. In tetanus the bacillus produces a 

 secretion of non-proteid toxin which causes the convulsions. The 

 albumoses present in this disease are probably due to the secretory 

 toxin. Ehrlich has isolated a spasm-producing toxin (tetanospasmin), 

 and a crude poison capable of destroying red blood cells (tetanolysin). 

 The nature of the tetanus toxin is not determined, but it is known 

 that it is a most powerful poison, probably less than -^t^^ of a grain 

 being poisonous to man. In diphtheria, too, we have a secretory 

 poison in the membrane and in the tissues, and an albumose which 

 is possibly the result of the secretion. But the true chemical nature 

 of the diphtheria toxin is also still unknown. In typhoid fever 

 intra-cellular bacillary poisons exist, and a toxalbumin has been 

 obtained which has pathogenic effects of an indefinite character. 

 The toxins of the typhoid bacillus appear to have little digestive 

 effect. 



Summapy of Toxic Effects. — The action of bacteria as disease 

 producers depends (1) upon the effects of the presence of the bacteria 

 themselves, and (2) upon their power of forming, directly or indirectly, 

 certain chemical organic products known as toxins. The effects of 

 the bacteria, though very diverse, may be classified generally as of a 

 necrotic or a separative character, leading to increased functional 

 activity at first (such as phagocytosis), and subsequently to in- 

 creased formative activity (such as cell growth and subdivision). 

 In most diseases the lesion has a special site (as in typhoid fever), 

 and the body generally is only affected indirectly. This locali- 

 sation may be due to specific action, or to point of entrance of 

 the bacillus (as in malignant pustule). Secondarily to tissue 



