REBREATHED AIR. 33 



tions by which bodies are formed of a poisonous 

 nature, or which act the part of a ferment in the 

 blood. 



We do not know precisely how rebreathed air 

 produces its deleterious influence, nor is it worth 

 while to stop to inquire, in this discussion. It is 

 certain that its effects are fatal to health. It would 

 be absurd to assert that the frightful prevalence of 

 consumption is due entirely to this agency ; as all 

 intelligent observers understand that there are many 

 causes operating to produce or develop this disease. 

 It is nevertheless probable that impure or re- 

 breathed air is the greatest agent of evil in induc- 

 ing, and rendering fatal, pulmonary affections. The 

 crowded, badly-ventilated school-room is often the 

 place where, early in life, rebreathed air commences 

 its deadly work. Not one school-room in a hundred 

 in this countrv is a fit place ^n which to confine 

 children six or eight hours of the day. The little 

 ones are herded together in a promiscuous crowd : 

 those of tender years* and those more advanced, 

 the feeble and the strong, the sickly and the well, 

 are all subjected to the same hours of study, the 

 same school discipline, and all breathe the same 

 deleterious air. The hardy and the strong may 

 be able to resist the influence of the poison ; the 

 weak and tender ones grow pale and haggard, and, 

 struggling on through their school-days, live per- 

 3 



