414 ON THE ORIGIN, PROPAGATION, 



sole survivor of his regiment, without scratch or contu- 

 sion. Shall we call him bullet-proof ? Will his safety 

 be ascribed to an absence of * predisposition ' to attract 

 the bullets thus enjoying an immunity which the 

 superstition of former ages would have ascribed to him ? 

 Is he more bullet-proof or less vulnerable than the com- 

 rade who by the first volley in the first battle was shot- 

 down ? ' How often,' says Cornet, ' do such cases repeat 

 themself in life ? and are we able to do more than de- 

 scribe them as accidents ? Unscientific as this word 

 may appear, it is more in harmony with the truth than 

 any artificial hypothesis.' 



The opportunities for incorrect reasoning in regard 

 to phthisis are manifold. It is observed, for example, 

 that a hospital attendant, who has had for years, even 

 for decades, consumptive patients in his charge, has, 

 nevertheless, escaped infection. The popular conclu- 

 sion finds vent in the words, ' It cannot be so danger- 

 ous after all ! ' Here, however, attention is fixed on a 

 single fortunate individual, while the hundreds who, 

 during the same time, have succumbed are forgotten. 

 The danger of infection in different hospitals is a 

 variable danger. In some we find bacilli, while in 

 others we do not find them. It is no wonder, then, 

 that among attendants who are thus exposed to differ- 

 ent degrees of danger, some should be infected and 

 others not. When, in cases of diphtheria, typhus, 

 cholera, small-pox, which are undeniably infectious 

 diseases, an attendant escapes infection, we do not 

 exclaim, ' They are not so dangerous after all ! ' But 

 this is the favourite expression when pulmonary con- 

 sumption is in question. ' When,' adds Cornet, with a 

 dash of indignation, ' we observe the enormous increase 

 of phthisis among the natives of Mentone, and find this 

 ascribed to the abandonment of land labour, instead of to 



