THE SANITATION OF AIR 25 



in buildings, is proved by a microscopic examination of deposits from 

 furniture, which shows a large percentage of animal refuse, mostly 

 horse offal, ground up by the street traffic. ' Dirt is useful matter in 

 a wrong place,' was one of the lamented Colonel Waring's maxims. 

 He had, indeed, not only succeeded in removing it, but was in a fair 

 way to make it pay for the cost of removal. Sanitation and economy 

 often go hand in hand. 



Concerted action is necessary to suppress this nuisance. No one 

 should complain about dust who is not doing his share in preventing it. 

 Each citizen must be his own sanitary officer and each sanitary officer 

 and employee must be made to attend to his duties on public property. 

 Corporations operating public conveyances should also be strictly held 

 up to their duties. A case which illustrates this point is the New 

 York Subway. Dust from the streets, mixed with sputum and sweep- 

 ings from within, are permitted to accumulate indefinitely on a road- 

 bed of gravel, which can never be thoroughly cleaned. The trains 

 continually stir up some of this accumulation and impart it to the air. 

 This is an inexcusable offense from a hygienic point of view. We need 

 only consider that an underground route has not, like a surface rail- 

 way, the natural assistance of wind, rain and sun in maintaining salu- 

 brity, and that it requires extra care and attention to make up for such 

 disadvantage. The drippings of oil will not altogether bind or lay 

 the dust, and the present method of drawing in air through dirty side- 

 walk gratings can not improve matters in this respect. An easily 

 cleaned surface and effective mechanical means should be provided to 

 keep the road-bed and the entire tunnel ' clean as a hound's tooth.' 

 The stuffy atmosphere often noticed in the subway is largely traceable 

 to these impurities, which are more objectionable than the heat and the 

 exhaustion of the air. The latter, after all, may be regarded as tem- 

 porary drawbacks, while dust and bacteria inhaled during the shortest 

 transit will cause infection, threatening disease to any one predisposed. 

 Unless built and operated with a reasonable appreciation of hygienic 

 science, subways may at times become a serious menace to public health, 

 especially when grip and similar epidemics are prevailing. 



Causes for Impure Air in Buildings. — Among the numerous factors 

 which may contribute to vitiate the air in buildings, some can always 

 be eliminated, while others are unavoidable and should be counter- 

 acted by ventilation, in one form or another. Acting on the principle 

 that prevention is better than cure, we should pay attention first to the 

 avoidable sources. Waste matter of any kind is certain to contaminate 

 the air without necessarily being perceptible by odor or by any of the 

 customary methods of testing. Dust and dried-up sputum from the 

 street, brought in by the air or by clothing, unless frequently removed, 

 will permeate carpets and draperies, from where it is continually 



