20 JOURNAL AND PROCEEDINGS 



cupants would die of suffocation in less than thirty minutes. 

 How few people realize this, or that the prime cause of con- 

 sumption is the breathing of impure and contaminated air. It 

 seems strange yet it is true, that our prisons are much better 

 ventilated than many of our churches and schools. Archi- 

 tects think more of the outward appearance of a building 

 than of its ventilation. A building with nothing but orna- 

 ment to recommend it is like a beautiful apple rotten at the 

 core. One of the most pressing needs of the present age is a 

 more general enlightenment on the subject of ventilation, and 

 an improvement in the ventilation of schools, houses, public 

 halls and churches. An epidemic comes and a few die from it, 

 a cry goes up from one end of the country to the other, while 

 hundreds die every year from the effects of breathing impure 

 air, and no complaint is made. In the open air we have noth- 

 ing to fear. Nature, by the principle of diffusion, provides 

 that any excess of impurities will soon become diffused. It is 

 in our houses, churches, public halls, schools and factories 

 that we have most to dread. Air that has been breathed 

 should not be breathed again, it becomes charged with carbon 

 dioxide and waste material from the lungs to such a degree as 

 to be very injurious, causing irritation to the mucous mem- 

 brane, and the delicate air vessels of the lungs. The most com- 

 mon impurity of occupied rooms is carbon dioxide, and the de- 

 gree of impurity of the air is generally judged by the percent- 

 age of this gas, because where it is found, you will also find 

 other impurities. When the proportion of carbon dioxide 

 reaches six parts in 10,000 it is positively injurious. It should 

 not exceed four parts in 10,000. Carbon dioxide formed from 

 combustion is not injurious except by exchiding oxygen, but 

 when the air is charged with waste animal matter from diseased 

 lungs, unclean bodies, dirty clothes, and dust, it becomes 

 positively injurious. An adult gives off from his lungs six- 

 tenths of a cubic foot of carbon dioxide per hour, which will 

 render 3000 cubic feet unfit for respiration from this cause 

 alone. At the same time we are using up the oxygen and 

 polluting the air with waste material from the lungs and body c 



