44 



The Ottawa Naturalist 



[June 



actually do penetrate the tissues and, like the Roentgen rays 

 and radium, do produce actual changes in tissues. Such rays, 

 we know, are obstructed and diffused Vjy vapor and clouds, 

 and in the summer, create with heat those conditions under 

 which fungi, as rust and mildew, develop on plants and in houses. 



I nfittence of Altitude. One of the most remarkable effects 

 of high altitudes, as in the Alps, is the notable 'increase 

 of red corpuscles in the blood. When one goes quickly 

 from sav Vera Cruz in Mexico to Mexico City, at 7,300 

 feet of altitude, in 12 hours, he is conscious at once 

 of exhaustion on the slightest exercise. The reason is that 

 the 4,000,000 corpuscles per cubic centimetre are not normally 

 capable of absorbing enough of oxygen to supply the needs of 

 the tissues, hence there is actually an anoxydation. Now it 

 is probable that the defective supply of oxygen which is rapidly 

 overcome, say in a fortnight, through an increase of the cor- 

 puscles to 6,000,000, or more is due to the bright sunshine. 

 Rapid metabolism or changes of tissue results, since to get enough 

 of oxygen deeper and more frequent inspirations invariably 

 and necessarily are the temporary effect. 



Thus we have here again rapid reconstruction of tissue 

 by increased demands for food, and the rapid increase of red 

 corpuscles is insured, provided that exhaustion is prevented by 

 temporary rest or slight exercise, and protection is insured 

 against a loss of body heat by adequate clothing, with the 

 very rapid fall of often 40 degrees of temperature within two 

 hours as sunset approaches. 



I have thus, as briefly as possible, indicated not only how 

 air or oxygen enters the system and produces effects there, 

 but have also shown how its normal constituents, oxygen and 

 moisture, and its abnormal contents, disease germs, produce 

 certain effects and how house atmospheres or excess of moisture, 

 cold, sunshine, and altitude all play their parts for good or ill 

 upon the human body. We have to deal now with actual 

 climatic conditions as we find them in Canada, and to indicate 

 some conclusions which seem to grow out of these. 



Remembering that in tuberculosis we have a disease which 

 yearly takes its toll of some 9,000 deaths in Canada, and realizing 

 that all sanitarians call it essentially a house-disease, increasing 

 directly with house density of population, we may properly 

 study it in relation to climate and in this include house atmos- 

 pheres or artificial climates. It will further be apparent that 

 whatever climatic conditions influence this disease, influence 

 probably equally other diseases. 



The problem of lessening tuberculosis presents two factors ; 



iKARY 



^^v^ 



.^^^ 



