188 PROTEIN POISONS 



found that solutions of cholin have a similar, but less 

 marked, solvent action on tubercle bacilli; also that these 

 solutions injected into men are without harmful effect. 

 Attempts to immunize animals with these solutions have 

 been made, without success. Aronson 1 has extracted fat 

 from tubercle bacilli with trichlorethylen, and has attempted 

 to immunize with the residue, but has not reported any 

 success. Calmette and Guerin 2 have tested the protective 

 action of tubercle bacilli grown on media containing bile 

 acids. They stated in 1910 that by the tenth generation, 

 these cultures of bovine tubercle bacilli become so attenu- 

 ated that they can be used as a vaccine. Since these 

 investigators have made no later report it is fair to assume 

 that their expectations have not been realized. Attempts 

 have been made to immunize animals to tuberculosis with 

 the virulent bacillus by beginning with so small an amount 

 as one bacillus (Webb and Williams) and increasing the 

 dose; with cultures attenuated in varying degrees; with 

 living and dead cultures of various varieties of the tubercle 

 bacillus, such as human, bovine, avian, chicken, from cold- 

 blooded animals, etc.; with strains of other acid-fast bacilli, 

 as those of timothy, butter, manure, etc.; with normal 

 and specific sera; but up to the present time no satisfactory 

 results have been obtained. This is an interesting subject, 

 and we would like to go into some detail, but it lies outside 

 the scope of this book. 



Lowenstein 8 has shown that the tubercle bacillus will 

 grow, though not abundantly, on a medium of the following 

 simple composition: 



Ammonium phosphate 6 parts 



Glycerin 40 parts 



Distilled water 1000 parts 



Although the growth is slow in developing and sparse, 

 it elaborates an active tuberculin. This is additional 

 evidence that growth of bacteria consists essentially of 

 synthetical processes. 



1 Berl. klin. Woch., 1910 No. 35. ' Comp. rend, de 1'Acad., cli, 1. 



s Centralbl. f. Bak., 1913, Ixviii, 591. 



