PLATE 23. 



Powers of resistance of the B. tuberculosis. 



a. A culture of the organism on glycerine-potato before exposure to liquid air. 



6. A sub-culture made after immergion of the organism in liquid air for a contiiiuons 



period of 42 days, 

 c. A sub-culture made after exposure of the organism to the temperature of liquid air 



for a continuous period of 42 days. 



JVbfe.— The temperature of liquid air may be taken as - 103= C. 



yt'ace page 252^ 



