VENTILATION. 
631 
evolves daily from the lungs no less than 13| ounces of 
carbon, a horse 79 ounces, and a milch cow 70 ounces. 
Upon what data the learned professor based these calculations, 
1 know not. I should be inclined, from a consideration of the 
foregoing details, to tix the amount at about 45 ounces of 
carbon daily, and the quantity of carbonic acid generated 
during this space of time to amount to 24 cubic feet. 
It must, however, be remembered that the excess of car¬ 
bonic acid is not the only product injurious to health in a 
stable. The exhalations from the skin and excretions, also the 
walls and ceilings in certain conditions, or defective drainage, 
all aid in producing a vitiated atmosphere. 
The maximum amount of the insensible cutaneous perspi¬ 
ration, including the pulmonary transpiration, has been esti~ 
mated by Lavoisier and Sequin at 2 5 6 grammes troy per 
minute = 3 ounces 1 drachm 36 grains per hour, or 6 
pounds 4 ounces 6 drachms 24 grains in twenty-four 
hours. The minimum quantity has been calculated at about 
one third this amount, viz., 8*8 grains per minute = 2 pounds 
2 ounces 3 drachms 12 grains in twenty-four hours; and 
the mean at 18 grains per minute = 4 pounds 6 ounces.* 
The pulmonary mucous membrane is said to average 
the amount of 3 grains per minute, or 9 ounces in twenty- 
four hours. 
The insensible cutaneous transpiration may be said to 
average 8’8 grains per minute = 26 ounces 3 drachms 12 
grains in twenty-four hours. 
An atmosphere saturated with moisture interferes with 
the cutaneous and pulmonary exhalations. In dry weather 
both are increased twofold. 
The sum of both secretions—the cutaneous and pulmo¬ 
nary—would amount to 2 pounds 11 ounces 3 drachms 12 
grains in twenty-four hours. 
In the horse, to about 14 pounds 9 ounces. 
The animal matter held in solution by this exhaled fluid 
enters very readily into putrefaction after it is excreted from 
the body, and hence the moisture becomes a vehicle for a 
subtle aerial poison, which, when breathed for a sufficient 
length of time, poisons the blood through the lungs, and so 
predisposes to disease. 
Thus, having established the following data—First, that 
a horse passes through his lungs 800 cubic inches of air per 
minute; secondly, that during twenty-four hours he will make 
45 ounces of carbon, or 24 cubic feet of carbonic acid gas; 
* Muller’s ‘Physiology,’ and Dr. Pickford, on ‘Hygiene.’ 
