TUBERCULOSIS 147 



nised, principally on account of the long time for which, as 

 pointed out above, the disease may be latent. 



In Germany and New York special regulations are in 

 force, and the disease is classed among those subject to 

 compulsory notification ; it will be a matter of deep interest 

 to see what success attends the somewhat stringent 

 measures which are being carried out in New York. 



In any experiments made to test the resistance of the 

 bacillus of tubercle to high temperatures or to the action of 

 disinfectants, the organism may be so attenuated that, if 

 inoculated on to media, it may not be possible to demon- 

 strate its vitality by culture within a reasonable time, and 

 in such cases it is much preferable to inoculate the material 

 to be tested for the tubercle bacilli into an animal such as 

 a guinea-pig or a rabbit — the former for preference. 



Nocard considers that the bacillus tuberculosis is the 

 same organism in man, cattle and birds, though modified 

 by its surroundings. To support this view, he states that 

 tuberculin can be prepared from all three varieties of the 

 bacillus which has the same properties and activity. The 

 following are the characteristic differences observable in 

 cultures : The bacilli derived from birds seem to be a 

 little longer than those met with in tuberculous mammalia, 

 they are stained by the same reagents and flourish on the 

 same media. The bacillus of birds seems to be more 

 vigorous in growth, and it grows at 43° C, at which tem- 

 perature the bacillus of human tuberculosis is arrested. 

 Its cultures on solid media are softer and more greasy, and 

 less tightly packed than those of human tuberculosis. 

 Tuberculosis avium is, according to Nocard, difficult to 

 inoculate into the guinea-pig, the dog, the sheep, and the 

 horse, but the rabbit is readily infected. 



Professor Bang's method for eliminating tuberculosis 

 from a herd of cattle depends on the fact that calves are 



10—2 



