538 MICRO-ORGANISMS AND DISEASE [chap. 



Erzeugung des Milzbrandcontagiums," Sitzimgsb. d^ math.- 

 phys. Classe d. K. Bair. Akad. d. Wiss. 1880, iii. p. 369). 

 We have in a former chapter described in detail the morpho- 

 logical and cultural characters of these two microbes and 

 have shown them to be sufficiently striking to- be readily 

 distinguishable one from the other. 



Buchner states that the bacillus anthracis when passed 

 through a large number of successive cultures at a tempera- 

 ture of 35° to 37° C. gradually loses its pathogenic properties. 

 In a Report to the Medical Officer of the Local Govern- 

 ment Board for 1881-1882 I have shown that, even 

 assuming that Buchner has had in all his cultures the true 

 bacillus anthracis, but for which there is no definite proof, 

 as Koch has so ably pointed out in his critical review of 

 Buchner's work (Mittheilungen aus dem k. Gesundheitsamte, 

 Berlin, 1881, Bnd. I.), Buchner, having tested his cultures 

 on while mice only, has fallen into a serious error, for, as I 

 have shown (Reports for 1881-1882), a culture of bacillus 

 anthracis may have become quite harmless to white mice, 

 but be still virulent to other animals. In fact, therefore, 

 Buchner's result does not require for its achievement more 

 than one culture, provided this has been kept for several 

 days or weeks without spore-formation, as was the case in 

 Buchner's experiments. 



As regards Buchner's statement that by successive cul- 

 tivation of bacillus anthracis at 35° to 37° C. this assumes 

 the morphological and physiological characters of hay 

 bacillus, I agree with Koch in regarding this as a complete 

 error. If the cultures are kept safe from contamination, 

 nothing of the sort ever happens. It is of course clear that 

 if by any accidental contamination, say at the time of inocu- 

 lating a fresh tube, a motile septic non-pathogenic bacillus, 

 with which, or with the spores of which, the air sometimes 



