66 



from beef by several hours' boiling. A local epidemic 

 occurred in Paris among the workmen who had handled 

 a cargo of hides from South America. 



The natural habitat of the anthrax bacillus has not yet 

 been discovered, though the plant is evidently indigenous 

 only in certain limited districts. Koch's researches, as 

 well as clinical observations, make it extremely probable 

 that the bacillus is not properly a parasite of animals ; 

 that it, like many other fungi, grows upon living or dead 

 vegetable matter, and its entrance into the cow or sheep 

 is merely incidental to the consumption of its host as 

 food by the animal an accidental excursion from its 

 usual life history just as the presence of the trichina 

 spiralis in the human subject is incidental to the con- 

 sumption of uncooked pork. 



When we reflect upon the close clinical resemblance 

 between anthrax and certain other infectious diseases ; 

 their occurrence sporadically and epidemically; their 

 usual limitation to certain conditions of climate and of 

 soil ; their especial prevalence during certain seasons of 

 the year; the predisposing influence of heat and moisture ; 

 the stage of incubation ; the contagiousness ; the self- 

 limitation of the disease, etc., it becomes evident to every 

 one whose cerebral functions are normally performed 

 that there may be, in this matter of bacteria, vastly more 

 than the optical delusions of a microscopist, the im- 

 practical fancies of a pathologist ; more than fat-crystals 

 and fibrin threads. Yet it is understood that there may 

 be no conclusions by analogy. Anthrax and septicaemia 

 may be very similar clinically and anatomically, yet the 

 demonstrated parasitic origin of the one does not prove 

 the same for the other ; arguments of that sort have no 

 place in exact science. The matter must be investigated 

 in the case of each disease independently, precisely as it 

 has been in anthrax a fact which is insisted upon by no 

 one more persistently and emphatically than by Koch 

 to whom, by the way, we are indebted for most of what 

 we now know about the life-history of the bacillus an- 

 thracis. And just here is another of those vital differ* 



