24 



TUBERCULOSIS, HEREDITY 



means that another 15 % to 20 % will heal in time. Even 

 this large number, shown by autopsy, was soon to be ex- 

 ceeded by von Pirquet's introduction of the tuberculin 

 test. He himself found by cutaneous reaction 55% of 

 children were tuberculous. Quite recently. Hamburger 

 and Monti, following the cutaneous test byaninjectional 

 one, have found 94% of Viennese children between 11 

 and 14 years to be tuberculous. They further state 

 that they have so far found no case of positive injectional 

 reaction which has not shown tubercle on autopsy. 



TABLE XII. PERCENTAGE OCCURRENCE OF TUBERCULOSIS 

 IN CHILDREN 

 as determined by 



Now 94% of children between 11 and 14 do not die, 

 even in Vienna, of tuberculosis ! The great bulk of 

 them recover and live to die of other complaints. But 

 the existence of this enormous mass of infected children 

 is, I think, sufficient to demonstrate the ubiquity of the 

 infection. Why in one of these children does the disease 

 develop to full intensity, but in another heal and the child 

 probably become immune ? I think that those who have 



