234 TUBERCULOSIS. 



toxines of tubercle are thus possibly not of the nature of 

 albumoses. Of their real nature we are still ignorant. From 

 what is known, it is possible that they do not to any great 

 extent diffuse out into the culture media. It has been 

 found that if tubercle cultures are filtered germ-free the 

 filtrate does not give such a marked tuberculin reaction as 

 the unfiltered fluid. Maragliano has found that such a fluid, 

 however, causes in animals lowering of temperature and 

 sweating, and further that if it is heated at 100 C. it now 

 gives a much more marked tuberculin reaction. From this 

 he infers that there is diffused out into the culture fluid a 

 body allied to the toxalbumins of Brieger and Fraenkel, 

 which is destroyed by heat, and which has a temperature- 

 lowering action. When this body is destroyed in a tubercle 

 filtrate, any intracellular poison which may be present from 

 the maceration of the bodies of the dead bacilli always 

 present in a growing culture, is unantagonised and now gives 

 the usual reaction. It is thus probable that more than 

 one toxic body may be formed by the tubercle bacillus. 



The Use of Tuberculin in the Diagnosis of Tuberculosis 

 in Cattle. This is now the chief use to which tuberculin 

 is put. In cattle, tuberculosis may be present without 

 giving rise to apparent symptoms. It is thus important 

 from the point of view of human infection that an early 

 diagnosis should be made. The method is applied asj 

 follows. The animals are kept twenty-four hours in their 

 byres and the temperature is taken every three hours, from 

 four hours before the injection till twenty-four after. The 

 average temperature in cattle is 102.2 F. ; 30 to 40 centi- 

 grams of tuberculin are injected, and if the animal be 

 tubercular the temperature rises 2 to 3 F. in eight to twelve 

 hours and continues up for ten to twelve hours. Bang, who* 

 has worked most at the subject, lays down the principle that 

 the more nearly the temperature approaches 104 F. the 

 more reason for suspicion is there. He gives a record of 280 

 cases where the value of the method was tested by subsequent 

 post-mortem examination. He found that with proper pre- 

 cautions the error was only 3.3 per cent. The method is; 



