THE BREATH OE LIFE. 
95 
requires ten cubic feet of fresh air per minute* ; a church, 
therefore, 80 feet long, 50 feet wide, and 40 feet high, and con- 
taining 1,000 persons, would require the whole atmospheric 
contents of the building to be renewed every sixteen minutes. 
A room containing a million cubic feet of air, in which were 
assembled 10,000 persons, would likewise require a total change 
every ten minutes ; and an apartment twelve feet each way, 
■with ten persons in it, would require an entire change of air 
every seventeen minutes. 
This quantity of ten cubic feet of air per minute for each 
individual, is what is required to supply him with the amount of 
oxygen necessary for the performance of the functions of respir- 
ation ; whilst the constant change of the atmosphere is impera- 
tively necessary to get rid of the products of respiration, viz., 
the carbonic acid and aqueous vapour, as well as the effluvia 
from the body ; for, disagreeable as it may be to refer to such 
a subject, this is the most noxious cause of contamination with 
which we are in the habit of coming in contact. “We instinct- 
ively,” says Bernan, “ shun approach to the dirty, the squalid, 
and the diseased, nor use a garment that may have been worn by 
another; we open sewers for matters that offend the sight and 
smell, and contaminate the air ; we carefully remove impurities 
from what we eat and drink, filter morbid water, and fastidiously 
avoid drinking from a cup that may have been pressed to the 
bps of a friend. On the other hand, we resort to places of 
assembly, and draw into our mouths air loaded with effluvia 
from the lungs and skin and clothing of every individual in the 
promiscuous crowd : exhalations, offensive to a certain extent 
from the most healthy individuals, but which, rising from a living 
mass of skin and lung in all stages of evaporation, disease, and 
putridity, and prevented by the walls and ceiling from escaping, 
are, when thus concentrated, in the highest degree deleterious 
and loathsome.” 
The evils produced by allowing the carbonic acid from the 
breath to accumulate in the air, have been already mentioned ; 
those engendered by inhaled animal effluvia are still more fatal 
in their results ; for, according to competent authorities, it seems 
to be an invariable result that the accumulation and stagnation 
of the breath and perspiration of human beings crowded for a 
period in confined air, and neglecting personal cleanliness, pro- 
duce plague or fever that may be communicated to healthy 
persons by contact or respiration. The most memorable 
* This is the minimum which should be allowed. In the House of Com- 
mons, which is, perhaps, the most perfectly, as it is certainly the most scien- 
tifically ventilated building in the world, Dr. Reid never allows less than 
thirty cubic feet of air per minute for each member, when the room is crowded, 
and on many occasions sixty cubic feet have been allowed. 
