Tu bercalosis . 417 



cases of tuberculosis in man and beast, life in a pure open air, 

 day and night, in a genial climate, gives the best hope of im- 

 provement or recovery. In the Burden Jersey herd above re- 

 ferred to, animals condemned in spring as tuberculous, were 

 turned out to pasture during the summer where they maintained 

 an appearance of robust health, yet when returned to the barns in 

 Fall they fell off rapidly, so that some had to be helped to rise in 

 the stall. " The stabled cow, the tame rabbit, the monkey, the 

 caged lion, tiger or elephant are almost invariably cut off by 

 scrofulous affection" (Aitken). It has long been noticed that 

 sailors sleeping in close spaces (Bryson, Parkes), soldiers confined 

 to close stone barracks even in the tropics (Parkes), suffer much 

 more than the officers in more spacious rooms (Clark). Monks 

 and nuns (two-thirds of the deaths, Leudet) occupying confined 

 cells, and the inmates of prisons (four times the average outside, 

 Baer) have shown an extraordinary prevalence of tuberculosis 

 and attendant mortality. While this can be attributed mainly to 

 the preservation and concentration of the bacillus in such places, 

 a considerable allowance must be made for the impure and re- 

 breathed air. 



Dark, Fotil, Damp Stables. Dark stables are usually close, 

 dirty and damp as well, and all these conditions alike conduce to 

 tuberculosis. Darkness hinders the development of organic 

 coloring matter in living bodies, whether chlorophyll in plants or 

 haemoglobin in the blood of animals. Haemoglobin is the main 

 oxygen carrier in the blood, and in case of its deficiency the tis- 

 sues are not properly aerated. The result is as if the inhaled air 

 contained little oxygen, so that darkness further intensifies the 

 evil of rebreathed, deoxygenated air. The extraordinary mor- 

 tality from tubercle among prisoners, monks, nuns and miners 

 serves to further accentuate this conclusion. 



Trudeau's experiment with rabbits is instructive in this con- 

 nection. Of a number inoculated with the same number of 

 tubercle bacilli, one half were kept in the operr air and the rest 

 in a dark, damp, underground place deprived of sunlight. When 

 killed on the same day, it was found that the open air rabbits 

 showed only slight lesions or none, while the underground lot had 

 extensive tuberculosis. 

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