xvii ] SEPTIC AND PATHOGENIC ORGANISMS. 157 



that hay bacillus can change into the pathogenic bacillus 

 anthracis (see Zopf, Die Spaltpilze^ Breslau, 1883). 



I have repeated Buchner's experiments on rabbits, guinea- 

 pigs, and white mice. I have grown the h.ay bacillus in 

 various kinds of broth, in gelatine broth mixtures, in hydro- 

 cele fluid, in peptone fluid, in Agar-Agar and peptone, at 

 temperatures varying between 30 and 38 C., and I have, to 

 put it shortly, never seen that it shows the least tendency to 

 change its morphological characters, or that it ever assumes 

 any morphological or physiological character like the bacillus 

 anthracis. I consider this a perfectly hopeless task, and I feel 

 sure any one might as soon attempt to transform the bulb of 

 the common onion into the bulb of the poisonous colchicum. 



But Buchner states that with his cultures of hay bacillus, 

 carried through many generations under varying conditions 

 of soil, he inoculated white mice, which died under symptoms 

 of anthrax, and whose blood contained the typical bacillus 

 anthracis. I do not for a moment doubt that he really had 

 mice dying from anthrax after inoculation with cultures of hay 

 bacillus, but I question the admissibility of his interpretation. 

 I believe that some accidental contamination of the culture of 

 hay bacillus with anthrax spores or otherwise may have 

 occurred and have got overlooked. How liable one kind of 

 infective material is to be invaded by foreign infective matter 

 may be understood from the following examples of its actual 

 occurrence. 



It is now admitted on all hands that the results of 

 Villemin in producing what is called artificial tuberculosis in 

 guinea-pigs, by inoculating the animals subcutaneously with 

 cheesy matter derived from human and bovine tuberculosis 

 or from a guinea-pig suffering from artificial tuberculosis, 

 cannot be produced by any other means ; it cannot be pro- 

 duced by ordinary, i.e. non-tubercular cheesy or other pus, 1 

 nor by setons (as once thought by Wilson Fox and Sanderson) 

 setting up chronic caseous inflammations in the skin of guinea- 

 pigs, nor by chronic mechanical irritation, e.g. insertion into 

 the peritoneal cavity of bits of gutta-percha or other substances 

 producing chronic peritonitis (as was thought by Cohnheim 

 and Fraenkel), but, as Cohnheim now tersely puts it, tuber- 

 culosis can be produced only by matter derived from a tuber- 

 culous source, and anything that produces this tuberculosis is 

 derived from a tuberculous source. Dr. Wilson Fox, after the 

 very important experiments performed by Dr. Dawson 

 Williams, according to which chronic inflammation in the 



1 Compare Watson Cheyne, Practitioner, April 1883. 



