638 
VENTILATION. 
experiments of Dr. Roscoe, who has shown that the beneficial 
action of the brick-and-mortar walls of our dwellings is not 
confined to the mere absorbing from or restoring moisture 
to the atmosphere, but that, it extends to a large, diffusive 
interchange between the carbonic acid gas of the apartments 
and the external atmosphere; that in fact, brick walls are 
powerful aids to ventilation. Dr. Roscoe ascertained that in 
a closed space, the air of which contained 16 per cent, of 
carbonic acid gas, 3*25 percent, escaped in two hours through 
the solid brick. 
In other words, the brick walls effected in No. 1 cavalry 
stable what the additional ventilators secured in the others. 
Gentlemen, I might enlarge on this very interesting theme, 
but I am afraid that I have already trespassed too long on 
your attention. 
Enough, I trust, has been shown to prove that a horse 
confined in a stable destroys rapidly so large a proportion 
of atmospheric air as to render it necessary that he should 
have a much larger cubic space than architects or builders 
have hitherto allotted to him; that the system of ventilation 
should be self-acting and of sufficient capacity, so as to 
enable the air of the stable to be changed three times during 
an hour; lastly, that the windows and doors should be looked 
upon as adjuncts to the self-acting system during times of 
extreme heat or stagnation in the outer temperature, and not 
as the main provisions for ventilation. 
The evils attendant on the want of ventilation are only 
too well known amongst us. A very large number of the 
diseases attendant on horses, cattle, and sheep, can mainly 
be attributed to, or are promoted by, an accumulation and 
stagnation of the exhalations of the body. 
If, therefore, man, in his provision for that part of the 
creation which administers to his wants, and furnishes him 
with his daily food, and contributes either to his amusement 
or sustains him in the day of battle, should possess any 
feelings of humanity, surely the least he can do is to give 
him air to sustain life as freely as light, with ingress and 
egress on all sides, and allow it to take its own course. Then 
may he exclaim with the poet— 
“ What delight 
To back the flying steed, that challenges 
The wind for speed ! seems native more of air 
Than earth ! whose burden only lends him fire ! 
Whose soul, in his task, turns labour into sport! 
Who makes our pastime his I” 
