ETIOLOGY AND PATHOLOGY. 193 



SO undeniably settled by experiment as some of the foregoing. 

 However, though not specially referring to anthrax, some 

 observations, made by M. P. Migale to the Academy of Sciences 

 in Paris, as the result of experiment with organized bodies 

 found suspended in the atmosphere, are quite compatible with 

 this mode of distribution and the pathology of anthrax. He 

 says : ' 1. The prevalence of organized corpuscles, which exceed 

 -o q\ tf millimetre in size, in the air, is low in winter, increases 

 rapidly in spring, remains almost stationary in summer, and 

 diminishes in autumn. 2. Kain arouses the organisms into 

 activity.' 



As we have before remarked, when speaking of the general 

 characters of anthrax, that all animals, though liable to be 

 affected by the disease, did not in every species and individual 

 show the same susceptibility ; so, in estimating the power of 

 the contaminating agent, we must not lose sight of the fact of 

 varying receptivity shown under various conditions by different 

 species and individuals. 



Instruments used at post-mortems, and in removing the 

 skins of animals improperly cleansed, are proved to have been 

 the means by which the disease has been conveyed to healthy 

 men and animals. 



To summarize what we have said respecting the causation of 

 anthrax : 1. We feel bound to give in our adhesion to the theory 

 which accepts the disease proper as the result of the action and 

 influence of certain living and particulate organisms upon the 

 different elements and tissues of the body, and thus it may be 

 classed as hsemal parasitism. 2. That this organism is a vege- 

 table — a bacterium — the bacillus anthracis. 3. That the bacillus 

 may enter the animal body, either by cutaneous inoculation, 

 by the digestive tract, or the air-passages. It is not distinctly 

 proved that an abraded surface is necessary, though in two at 

 least of the foregoing media it would seem probable. 4. That 

 a certain condition of animal system is necessary to form a 

 suitable pabulum for the operation of the poison, and that 

 circumstances favourable to the production of this condition 

 are also favourable to the existence and activity of bacillus 

 anthracis. 5. That though under certam circumstances this 

 organism may lose its vitality — as in the presence of bacterium 

 termo, the germ of putrefaction — it resists extremes of low 



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