Year: 1865

lferous mines, DR.. Angus Smith eX>
amined the quality OF the air which the


miners have to breathe, to the impuriiy
Of which is chiefly attributable the early


breakdown in their strength. A healthy
atmosphere may be taken to be one with
.20.9 per cent. of oxygen, and -04 per
cent. of carbonic acid gas. Late in the
evening in the pit of London minor thea
tiers as much as 0,252 and 0-320 per cent
of carbonic acid has been found; but the
average of above three hundred samples
of air taken from these mines had 0-785.


Two thirds of the samples presented an
atmosphere exceedingly bad, and the
worst parts of the mines bad only about


1860 per cent, Of oxygen, and as much
as s or more of carbonic acid, in one
instance 2-2G per cent.


In order 20 test the effects Of such bad
air DR.. Smith caused to be constructed a
small close chamber Of lead, with win
dows sufficiently large that they might in
any emergency be broken through for a
way of escape. The first trial was made
by sittiog down in the chamber for an
hour and forty minutes. This produced
about l per cent. of carbonic acid, and
the air became cherries. A young lady
was anxious to be in the chamber when
the air was such that candles would not
burn. She was not much struck by the
impurity of the air on entering, although
the candles were threatening to 90 out.
There was not quite 10 per cent. Of oxy'
gen, and there was rather more than two
per cent. of carbonc acid. No one had
been breathing in the chamber, so that
organic matter from the person was alb
sent, and that makes a great difference.
She stood five minutes perfectly well,
making light of the difficulty, but sud-
denly became white, and could not come
out without help.


On another occasion a still greater
amount of carboic acid was present in the
chamber, but it was not accompanied
with corresponding loss of oxygen, for
the gas was driven in upon pure, air /;
there were 20.l9 per cent. of oxygen,
with 64 of earbonic acid. Two per-
sons got headaches instantly and were
unable to stay above seven or eight
minutes. DR.. Smith stayed about twenty
minutes, but felt very anxious to get out,
as his movements were made with great
haste, and both mind and body betrayed
symptoms of (everish activity. The face
was flushed, and the lungs acted more
rapidly than usual. In fact, there was
a burning haste to live, as if life were
afraid of being put out. 1t seems to him
to endure four per cent. Of
carbonic acid for any length of time
There was very remarkable lowering
of the pulse, aud as this happened reg
ularly he puts it down as the result of
poisoning with carbonic acid gas, and
asks whether it may not suggest mode
of lowering the pulse in a fever.


These experiments show the great
that must arise from the impure,
air in metalIferous mines.
The men call it "lhin,' "poor," "dead =
the effect is slow poisoning. The ex>
pIosions Of gundowder produce sulphde
of potassium, the effect of which is prob.
ably like that of sulphde of hydrogen,
but from its acting more slowly there is
distributed over a long period that death
which might ensue instantly, and so, in
chemical phrase, the effect is dissolved in
health, and becomes disease. Gun cot
ton seems to promise to perform the work
Of blasting with less injurious influence
upon the air.


In the coal districts, where on account
of the dangerous gases, great attention
has been given to the proper ventilation
of the mines, the mortality (accident ex-
cepted) is considerably less than in the
districts, and this shows
that the excessive mortality in the latter
is not caused by the mere working un.
der ground in dark galleries.


DR.. Smith touches incidentally, in bis
report upon various points of practical
importance. He notices the purifying
effect of rain upon the air, of which there
was such a scarcity last year. Moisture
with a high temperature improves the
air, and be holds that cold and moisture.
in such amounts as those in which they
are found in Great Britain are capable
of producing powerful constitutions. and
that the more watery districts of the king
dom present in many instances the most
healthy spots. Still, in relation to VEN
tilation be says that "chemical action, and
with it the feelings, demand a certain
amount of warmth first and above all
things. No function can go on without
It. You may live hours, days, or years
in bady-ventilated places with more or
less discomfort and danger, but draft
of cold air may kill like a sword. 10
railway carriages, in houses also, the
great instinct Of man is first to be warm