CHAPTER II 



BACTEKIAL POISONS 



WHEN bacteria have gained a foothold anywhere within the 

 animal body the local and general disturbances which follow, in all 

 but the mildest and most trifling cases, are such that we cannot 

 account for them solely on the basis of mechanical injury. 



It may well be that the obstruction of capillaries and lymphatics 

 and the pressure upon parenchyma cells, always incident to inflam- 

 matory reactions, contribute materially to local destruction, and 

 thereby indirectly to systemic effects. However, even in diseases 

 like anthrax, in which the body of the victim after death is found 

 flooded throughout with masses of bacteria, these factors cannot fully 

 explain the clinical manifestations. And such cases, indeed, ara 

 extreme examples, since, in the large majority of bacterial diseases, 

 the illness resulting in the patient is severe out of all proportion to 

 the extent of the tissue area invaded. 



Moreover, all infections, if at all severe, whatever their nature 

 or localization, give rise to fever, and this symptom alone, if care- 

 fully observed from hour to hour, may be sufficiently characteristic 

 to indicate the specific micro-organism which is causing the illness. 

 With this there occur alterations of the blood picture, either a 

 numerical increase of white blood cells (leukocytosis) or a change in 

 the relative proportions of the different kinds of leukocytes or 

 again an anemia caused by the destruction of red cells. There may 

 also be degenerative changes in parenchyma cells of organs far re- 

 moved from the actual site of bacterial lodgment. All these facts 

 indicate very definitely that, apart from localized tissue destruction 

 or purely mechanical interference with function by capillary ob- 

 struction or pressure, there is at the same time an absorption of 

 poisonous substances emanating from the bacteria. 



From the earliest days of logical investigation into the nature 

 of infectious disease, as soon, in fact, as cultural methods had been 

 introduced, bacteria were studied with the purpose of throwing light 

 upon this phase of their activity. As a result of such investigations 

 Selmi, 1 in 1885, described certain basic toxic substances which he 

 obtained from putrefying human cadavers and for which he sug- 

 gested the designation "ptomain" (from rrrw/xa dead body). These 



1 Selmi. Cited from Hammarsten, "Textbook of Phyaol. Chem.," p. 16. 



