228 



THE AMEKICAN MONTHLY 



[December, 



way, do not produce contagious dis- 

 eases. 



But if the atmosphere carries the 

 ms of disease, it is not unlikely 

 that these will be most active where 

 Vhe air is impure. For, if these be 

 germs of living organisms, they will 

 doubtless find a suitable nidus for 

 growth and multiplication where de- 

 composition is going on, and they 

 will be disseminated by the rising 

 gases. It is very likely that some of 

 them increase in virulence when they 

 grow shielded from the free access of 

 air. But so long as the germs are 

 absent, sewer gas or effluvia of any 

 kind will not generate contagia. 



About three years ago Professor R. 

 O. Doremus read an article before the 

 Medico-Legal Society of New-York, 

 entitled "Epidemies from a Chemi- 

 cal Standpoint." In the experiment 

 which he then performed the perme- 

 ability of sandstone, brick, etc., to 

 gases was demonstrated. This fact 

 is well known to chemists, but the 

 experiment proves nothing more than 

 that the poison of contagia may be 

 retained by the porous walls of houses. 

 It should not be inferred, however, 

 that the contagia are able to pass 

 through the stone, for that has not 

 been proved and is, indeed, highly 

 improbable. 



Experiment indicates that all the 

 floating germs of contagious disease 

 may be filtered from the air by means 

 of cotton. Gun-cotton can be em- 

 ployed for this purpose, after which 

 it can be dissolved and the germs 

 will settle to the bottom of the solu- 

 tion where the microscopist can find 

 them. There are also other methods 

 of collecting them for examination. 

 The microscopic examination of air 

 is, therefore, very important. But it 

 should only be entrusted to careful 

 investigators — persons who are not 

 too hasty in drawing inferences from 

 experimental results. The more one 

 studies the microbes of the air, the 

 more fully he realizes the immense 

 field to be gone over before the re- 

 sults can be properly interpreted. To 



definitely declare the relation between 

 these microbes and specific diseases 

 now, indicates a very superficial knowl- 

 edge of the subject. For it is im- 

 possible to distinguish by sight be- 

 tween a bacterium that is virulent 

 and one that is harmless. 



The results of experience may, 

 therefore, be summed up in a few 

 words, thus : We have no means of 

 determining when a water, which an- 

 alysis shows is liable to become a 

 carrier of disease, does become active 

 in its dissemination, nor can we yet 

 determine whether the air we breathe 

 is or is not loaded with the germs of 

 disease. 



But we cannot doubt that after 

 years of continuous observation by 

 competent persons, satisfactory results 

 will be obtained. I regard it as a 

 national misfortune that the National 

 Board of Health has been unable to 

 secure an appropriation adequate to 

 continue its work and the publication 

 of the Bulletin. 



Sceptics may question the value of 

 these investigations, but let us look 

 for a moment at the actual results in 

 saving human life, shown by the 

 statistics of England and Wales for 

 successive periods of ten years since 

 1 84 1. The annual death rate for 

 those countries for ten years, from 

 1841, was 22.4 in 1,000 persons ; for 

 the next ten years it was 22.2, and for 

 the next ten years, up to 1870, it was 

 22.5. For thirty years, therefore, it 

 remained quite stationary. Then 

 sanitary science was applied to dimin- 

 ish the death rate, and in the next 

 ten years, from 187 1 to 1880, it fell 

 to 21.5. This represents the saving 

 of a quarter of a million lives. A 

 further examination of the statistics 

 also shows that this saving of life is 

 in great part due to the effect of sani- 

 tary laws upon the prevalence of cer- 

 tain zymotic diseases. In exact figures, 

 0.78, or more than three-fourths of 

 the improvement is due to this alone. 

 The fever death rate has fallen from 

 0.80 per 1,000, in 1870 to 0.32 in 1880. 



Another subject, upon which there 



