428 WAENING "NOTE." 



light and leading of such investigations as that which 

 is here so imperfectly described. 



Your obedient servant, 



JOHN TYNDALL. 



HIND HEAD, April 20, 1882. 



NOTE. 



Twenty years ago I received letters describing to me the grief 

 and ruin introduced into families through the notion, then preva- 

 lent, that typhoid fever is non-contagious. When Dr. William Budd 

 published his researches on this subject, showing by facts and 

 reasonings as cogent as it was in the power of science to supply, 

 the infectiousness of the fever, certain writers discerned in that 

 important work a proof of the decadence of Budd's intellect, and 

 gave the public the benefit of their conclusions. 



In regard to the contagiousness of phthisis, we have now, it 

 seems, to face the same danger. It may not, therefore, be out of 

 place to cite an illustration of the recklessness stimulated by the 

 assertion that 'consumption is not an infectious disease.' While 

 occupied with experiments on the inhalation of tuberculous air by 

 dogs, Tappeiner was assisted by a robust man of forty, who was 

 specially warned never to_tarry in the locality where the dogs were 

 confined. He, however, seemed bent on proving the doctrine of 

 tubercle-contagion to be a delusion, and recklessly exposed himself 

 to the infective air. This strong man, who was free from any 

 suspicion of hereditary taint, was smitten by tuberculosis of exactly 

 the same kind as that exhibited by the dogs, and in fourteen weeks 

 he was a corpse. Examination after death proved the identity of 

 the disease which killed him with that which affected the dogs ; 

 the only difference being that he, having lived longer, exhibited the 

 malady in a more advanced stage. (October, 1891.) J. T. 



