418 BACTERIOLOGY. 



cerned in the production of the so-called "hemorrhagic 

 septicaemias." When running their normal course these 

 organisms cause typical septicaemias after having been 

 introduced into animals, but often, from causes not en- 

 tirely clear, the animals die with only local lesions, or 

 with but very few organisms in the internal viscera. We 

 see here conditions analogous to those observed in the 

 two experiments with anthrax, viz., we find a group of 

 diseases that are properly classed as septicaemias, because 

 of the usual general invasion of the body by the organ- 

 isms concerned in their production, but which frequently 

 assume a purely local character in both instances prov- 

 ing fatal to the animal infected. From what we have seen 

 it is manifestly probable that, whether these diseases be 

 designated as septicaemias or septic troubles, or toxaemias 

 or toxic troubles, death is produced in all instances by 

 the poisonous products resulting from the growth of 

 the infecting bacteria. In the case of typical anthrax, 

 and other varieties of septicaemia, the production of this 

 poison is associated with the general dissemination of 

 the organisms throughout the body, while in those infec- 

 tions often referred to as toxaemias, of which diphtheria 

 may be taken as a type, the poison is produced by the 

 organisms that remain localized at the site of invasion, 

 and is from thence disseminated throughout the body 

 by the circulating fluids. 



Infection thus far, then, appears to be a chemical 

 process. 



Through special investigations that have been made 

 upon the products of growth of certain pathogenic bac- 

 teria, this opinion has received further confirmation ; 

 it has been found possible by the use of appropriate 

 methods to isolate, from among the mass of material in 



