88 JOHNE'S DISEASE 



broth or agar. These, as a rule, did not give such 

 good results, although ordinary glycerine-peptone- 

 bouillon, made distinctly alkaline and containing 

 i to I per cent, of dried tubercle bacilli, gave a 

 fairly satisfactory growth. This, with other ex- 

 periments to be described later, proved that 

 Johne's bacillus can grow quite well in the absence 

 of albumen." 



In the same paper, p. 537, we wrote : 



" As has been stated, no growth occurs on any 

 of the artificial media in general bacteriological 

 use, such as peptone-bouillon, agar, gelatine, serum, 

 potato, or eggf even when such substances as 

 glycerine, sugars, amino-acids, fresh blood, etc., 

 are added. It is absolutely essential that certain 

 previously detailed bacteria or extracts from them 

 be added to one or other of the media, before any 

 growth of Johne's bacillus takes place, and this is 

 equally true for strains of Johne's bacillus which 

 have been freshly isolated from the animal body, 

 and for stains which have been cultivated on 

 artificial media for fifteen months or more." 



From the quotations given it will be seen that the 

 question of obtaining a clear medium and one free 

 from the bodies of tubercle bacilli, or allied bacilli, was 

 fully considered in the paper to which we have referred, 

 and, as we also pointed out, the " essential substance " 

 in these bacilli can be extracted more efficiently by hot 

 alcohol than by glycerine if a Soxhlet's apparatus is 

 used when extracting with the former. In another 

 part of their paper M'Fadyean, Sheather, and Edwards, 

 mention some of these experiments. 



In their paper {Journal of Comparative Pathology^ 

 vol. XXV., part iii.) M'Fadyean, Sheather, and Edwards 



