12 DR. E. KLEIN. 



ultimately entrance into the body of an animal grazing on that 

 field. Hay infusions and other vegetable matter, it is true, 

 owing to their acid reaction, do not, according to Koch, form 

 a suitable nourishing fluid for the Bacillus anthracis ; but 

 Koch draws attention to its being a known fact that the 

 dangerous anthrax localities have a chalky or loamy soil, and 

 it is therefore possible that even where the vegetable infusions 

 in the soil would be acid (hay, some kinds of straw, barley, 

 grass, &c.), the carbonate of lime of the chalky soil would 

 suffice to neutralise the infusions. 



Koch (1. c, p. 25) failed to find any diminution in viru- 

 lence of the Bacillus anthracis cultivated artificially up to 

 the fiftieth successive cultivation, an experience which I am 

 able, as I shall presently show, to confirm. 



Before I give a detailed description of my own observations 

 on the cultivation of B acillus anthracis, I have to state 

 the method of cultivation which was employed in this inquiry. 

 As nourishing fluid I have employed broth prepared from fresh 

 pork. About a pound and a half to two pounds of pork are 

 boiled in water for an hour or so down to about two pints of 

 fluid. The fat scum is removed, and the fluid, provided the 

 pork employed has been lean, filters tolerably clear through 

 filter paper. To obtain it, however, perfectly limpid, the broth 

 is cleared a la cuisine with egg-albumen and then filtered. 

 The filtrate, which will be spoken of as " the pork broth," is 

 of a neutral or faintly acid reaction ; in this latter case a suffi- 

 cient amount of carbonate of sodium is added in order to make 

 it neutral ; it is then received in long-necked flasks, which are 

 then plugged with cotton wool. 



In all cases, and I wish to state this once for all, where a 

 cotton-wool plug is spoken of, whether in connection with a 

 flask or a test-tube, it will be understood that a cotton-wool 

 plug of about two inches length is meant, in some instances 

 two plu<is one above the other, each about an inch long, being 

 used. The cotton wool, the flasks, beakers, filters, filter paper, 

 test-tubes, and all vessels used, are invariably disinfected by 



