80 JOHNE^S DISEASE 



Dried human tubercle bacillus gave good results, 



but inferior to B. phlei. 

 Dried bovine tubercle bacillus gave negative 



results. 

 Dried swine tubercle bacillus gave negative 



results. 

 Dried tubercle of uncertain source, freed from 



wax and fat, gave negative results. 

 Dried tubercle of uncertain source, freed from 



wax, fat, and proteid, gave negative results. 



The timothy-grass bacillus and the human tubercle 

 bacillus were found to be equally good when previously 

 autoclaved in normal saline for thirty minutes at 

 120° C. The results proved conclusively that the 

 "essential substance" contained in these bacilli is 

 comparatively stable, remaining undiminished in the 

 timothy-grass bacillus and the human tubercle bacillus 

 that had been killed and dried eight years previously, 

 and also after they had been autoclaved. It is inter- 

 esting to note that the bovine type, when added to 

 media, again gave negative results, and that the 

 bacillus of uncertain source, which had been extracted 

 with acid-alcohol, etc., also failed to give any growth 

 with Johne's bacillus. 



We now took i gramme of the dried B. phlei 

 powder, and extracted with 20 c.c. of 0*8 per cent, 

 sodium chloride in redistilled water containing 4 c.c. 

 of glycerine. The mixture was autoclaved for half an 

 hour at 120° C, and then filtered. The filtrate was 

 added to the yolk and white of hens' eggs in the pro- 

 portion of I part of filtrate to 3 parts of egg. The 

 residue was washed several times with normal saline, 

 dried, and made up into medium with egg^ so that 

 J per cent, of the residue was present. The same 

 process was followed with another gramme of the 



