824 THE POPULAR SCIENCE MONTHLY. 



tlie same way, tlie deaths of the Black Hole of Calcutta add their 

 evidence, though it is an evidence of an extreme kind. While out 

 of the one hundred and forty-six persons shut up, one hundred 

 and twenty-three died, of the remaining number (Carpenter, page 

 357) many afterward died of putrid fever — that is, were poisoned, 

 owing to an insufficiency of oxygen to neutralize the poisons 

 breathed out on all sides of them, and rebreathed by themselves. 

 A much simpler piece of evidence is presented to us daily by our 

 own eyes. Who is not struck by the pasty, antemic look of our 

 city children, and of the large number of those who follow seden- 

 tary occupations, as contrasted with the looks of those who live 

 in the country and are much in the open air ? What is that 

 pasty, anaemic look ? It is the absence of red corpuscles from the 

 blood, indicating that where oxygen is deficient * the red corpus- 

 cles are not produced in their proper quantity. So also the effects 

 of living in rooms in which sewer-gas has penetrated illustrate in 

 their own stronger degree the effects of living in unventilated 

 rooms. The one is the lesser form, the other the more serious 

 form of the same evil. In both, bacteria thrive and multiply, 

 and in both, meat and milk rapidly taint. They are both full of 

 organic matter, and the symptoms of headache and feverishness 

 are common to both, though, of course, the case of sewer-gas is 

 much the more acute case. \ Again, we all know the wonderfully 

 restoring effect that hill air with its ozone has upon us after town 

 life ; showing how the poison has depressed all our functions, and 

 how the pure air restores their energy. We see the same effect 

 in the lives of work-people. Sir D. Galton, as we have seen, tells 

 us of better work done, more energy, more appetite, when air is 

 introduced into unhealthy work-rooms. Dr. Parkes tells the same 

 story. Dr. A. Ransome, speaking in 1875, quotes the case of the 

 Guards, picked men, highly cared for, yet who died quite as fast 

 as the civil population. Why ? he asks. Mainly from defective 

 ventilation of the barracks (Health Lectures, 1875-'78, page 150). J 



some hundreds of glass panes in the windows, so as to admit air freely. After that the 

 wounded recovered rapidly."— (L. P.) In the same way Dr. Clifford Allbutt reduced the 

 mortality in a heavy epidemic of typhus fever in Leeds by fastening the windows in the 

 fever hospital with screws, so that they could not be shut. He remarks that in Ireland 

 those attacked with typhus, who were put out to die, would often recover. 



* But why is oxygen deficient in these cases ? Is it, once more, because so much or- 

 ganic poison is breathed in with the air of the shut-up rooms, that the, functions are de- 

 pressed and imperfectly performed ; that, for example, the act of respiration is impaired ? 

 Or does the poison directly affect the formation of the red corpuscles ? 



\ It has, however, been shown recently that the air in a well -ventilated sewer is, so far 

 as organic matter and micro-organisms are concerned, purer than the air in a small, badly 

 ventilated room. 



X " Sir Lyon Playfair, one of the commissioners for inquiring into the state of barracks, 

 passed a couple of nights with the soldiers m their crowded sleeping-rooms, and found the 



