No. 4.] TUBERCULOSIS. 341 



their reproduction. Consequently, in the majority of cases 

 the germs do no harm. 



These dangers, — whether from physical mishap or germs, 

 — are so common and the individual risk so slight thai we 

 go about our daily duties without fear, maybe carelessly; 

 we know that even in the ease of war a large majority of the 

 persons who go to the front return alive. Even though a 

 horrible ocean calamity, bringing hundreds to an untimely 

 end, sends a thrill of horror through the community, the 

 steamers next sailing are loaded with passengers, each one 

 believing that the probabilities of a similar accident happen- 

 ing to him are very slight. The railroad accident, causing 

 many deaths, does not decrease travel. In other words, 

 these various possibilities of injury or death create no panic 

 or scare in the community. But, on the other hand, they 

 are not viewed with stolid indifference. They lead to extra 

 precautions and increased safeguards. 



Though the railroad accident does not cause any decrease 

 in railroad traffic, though the public, with what appears to be 

 almost reckless carelessness, journeys the next day as if 

 nothing had happened, the accident does not pass unheeded. 

 Its causes are carefully studied, the dauger of a similar 

 occurrence is investigated, and the expert mechanic in his 

 workshop and study evolves an air brake, an interlocking 

 switch, an automatic signal or some other safety appliance; 

 and traffic is all the more safe as a result, but without panic. 

 The ocean horror sets investigators to thinking, and some 

 one devises new means of signalling, invents new processes 

 for increasing safety in a fog, or suggests new paths for the 

 ocean traffic. The falling of an electric wire, causing the 

 death of a passer-by, or the crossing of an electric light wire 

 with a telephone wire, setting fire to valuable buildings, does 

 not decrease the use of electricity, and the dangers therefrom 

 are not vociferously advertised, to alarm the public ; but 

 careful investigation follows, then come days and nights of 

 study and experiment, and finally some expert electrician 

 devises a method for insulating the wires or for operating 

 them satisfactorily under ground; the danger disappears, 

 while the comfort resulting from the use of these modern 

 conveniences increases. 



