414 ON THE ORIGIN, PROPAGATION, 



the sole survivor of his regiment, without scratch or con- 

 tusion. 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 su- 

 perstition 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 re- 

 peat themselves in life ? and are we able to do more than 

 describe 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 different 

 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 fa- 

 vourite expression when pulmonary consumption is in 

 question. "When," adds Cornet, with a dash of in- 

 dignation, " we observe the enormous increase of phthi- 

 sis among the natives of Mentone, and find this as- 

 cribed to the abandonment of land labour, instead of to 



