April 7, 1916.

THE COLLIERY GUARDIAN.

653

said, while planning the paper the authors considered
whether they should make a comparison between the
capital cost and working expenses of a turbo and a
reciprocating installation of the same capacity, but they
abandoned the intention on the ground that it was rarely
permissible to publish the figures relating to actual
installations. Fortunately, Capt. Percy Muschamp had
published the actual results obtained with the New
Hucknall compressor, which was capable of compressing
7,500 cu. ft. of free air per minute to 801b. pressure, and
was estimated to effect a saving of a considerable
amount of fuel per annum, about .£2,000 a year, taking
the value of coal at 5s. per ton. The total cost amounted
to nearly £10,000, whereas the necessary addition to the
original compressor plant at New Hucknall would have
involved an expenditure of about £3,500, but would have
given only half the quantity of air as compared with the
turbo-compressor plant. By spending the extra £6,500
a saving of over £2,000 per annum had been obtained,
which was equal to about three years’ purchase on the
extra capital expenditure, or five years’ purchase on the
total cost. From each 25,0001b. of exhaust steam per
hour 1,000 horse-power could be extracted; and many
large collieries would have from three to four times this
amount.

These and other facts were cited from Capt.
Muschamp’s statement by Mr. Guy, who observed that
the plant described was started up in August 1912, and
latterly the New Hucknall Company had ordered a
duplicate plant to be installed at another plant. He
emphasised that the saving of £2,000 per annum for
an additional expenditure of £6,500, less the cost of two
extra boilers, was based on a coal price of 5s. per ton,
and he would leave to the members the necessary
correction in the saving with coal at its present price.

The authors were cordially thanked for their paper.

The consideration of a new paper on “ Steam Plant
Efficiency,” by Mr. Vernon Smith, was deferred until
May 18, at Cardiff.

The proceedings closed with a vote of thanks to Mr.
Sevier for his services in the chair, on the motion of
Mr. T. Sugden.

PRICE OF COAL (LIMITATION) ACT.

The following correspondence lias passed between the
Institution of Gas Engineers and the Board of Trade :—

; The Institution of Gas Engineers,

39, Victoria-st., Westminster, S.W.,

March 17, 1916.

Sir,—The attention of the Institution of Gas Engineers
has been called to the correspondence which has recently
passed between you and Sir Thomas Ratcliffe-Ellis as to
. the interpretation of the Price of Goal (Limitation) Act.
It is found that the collieries are interpreting this corre-
, spondence to mean that they have the right to take as the
basis price in all cases the highest price obtained from
any purchaser for similar quantities.

This, it seems, cannot be the true intention of the Act,
for it would mean that in all cases buyers would have to
pay the price most advantageous to the colliery, the result
being that the colliery would obtain considerably more than
4s. per ton on the average. Furthermore, it would mean
that if there had been exceptional circumstances which
would ^warrant the obtaining of a higher price in any
particular case, all buyers of the same coal would forfeit,
although the same circumstances would not necessarily
apply to their cases.

It is felt that the only way of giving real effect to the
Act, and limiting the increased price to 4s. over the average
is that the price by an individual purchaser shall be com-
pared, for the purposes of the Act, with the previous prices
paid by that same purchaser (provided a purchase has been
made); otherwise, as pointed out above, by taking as the
basis price the highest price obtained, the buyer would be
heavily penalised.

Awaiting the favour of your reply, I remain, your
obedient servant, (Signed) John Young, president.

W. F. Marwood, Esq., C.B.,

Board of Trade, 7, Whitehall-place, S.W.

Beard of Trade (Bailway Department),

7, 'Whitehall-gardens, London, S.W.,

March 20, 1916.

Sir,—In reply to your letter of March 17, regarding the
Price of Coal (Limitation Act), I am directed by.the Board
of Trade to state that while, as pointed out in their letter
to Sir T. B. Batcliffe-Ellis, to which you refer, there is
nothing in section l(i.) of the Act requiring that reference
should in all cases be made to sales to the same buyer,
such sales would probably, as a rule, be more likely to
have been made under similar “ conditions .affecting the
sale ” than sales to other buyers.

The exact determination of the corresponding price may
sometimes be difficult, and the Board hope that both buyers
and sellers will be ready to interpret the Act reasonably,
and not require reference to contracts under which the
price was either unusually high or unusually low owing
to special temporary circumstances which may have
existed at the time.

The Board are always willing to offer an opinion on any
case that may be referred to them by the parties.—I am,
sir, your obedient servant, (Signed) W. F. Marwood.

The President, The Institution of Gas Engineers,

39, Victoria-street, Westminster, S.W.

Russia’s Mineral Resources. — According to a Russian
paper, an English company of capitalists has discovered large
coal beds near Sviereff station, on the South-Eastern Bail-
way. Shafts are being rapidly equipped to work them.
Bussian capitalists are also prospecting in the district.—The
council of the Congresses of Business Exchanges has
examined the problem of developing the iron industry in
Siberia. It has been shown that the richest deposits of iron
ore and coal in Siberia are to be found in the Yenissei and
Kuznetzoff districts, in which all the required conditions for
the establishment of an iron and coal industry exist.

ACCIDENTS FROM POISONOUS
ASPHYXIATING GASES IN MINES.*

By L. G. Irvine, M.D.

The important abnormalities and impurities which
may be found in the air of mines are the following :—

(1)	Deficiency of oxygen.

(2)	Carbon dioxide, CO2.

(3)	Methane, CH4 (firedamp).

(4)	Carbon monoxide, CO.

(5)	Nitrous fumes, mainly N02.

(6)	Sulphuretted hydrogen, H2S, and sulphurous

acid, S02.

Apart from nitrous fumes poisoning, which only occurs
in the use (or abuse) of explosives, the danger to life in
accidents from gas poisoning in mines arises almost
entirely, either from a deficiency of oxygen in the atmo-
sphere breathed, or from the presence of carbon
monoxide.

In accidents due to the fumes of explosives, carbon
monoxide accounts for most of the deaths, but nitrous
fumes poisoning may also result, and is the charac-
teristic form of poisoning in accidents due to the inhala-
tion of the fumes of burning nitro-glycerine explosives.

In mines where compressed air is used underground,
for example, accidents have from time to time occurred
from overheating of the air compressors, and conse-
quent “ firing ” of carbonised oil residues. The air
distributed to the faces in these circumstances may
become charged with dangerous quantities of carbon
monoxide. In one accident of this nature, which
occurred some years ago on the Rand, 10 lives were lost
from carbon monoxide poisoning.

Gassing Accidents Arising from the Fumes of Explosives.

With a very few exceptions, all of these accidents arise
from the fumes of nitro-glycerine explosives, of which
very large quantities are employed daily in mining
operations. It may be regarded as certain that a
dangerous amount of carbon monoxide is not only an
occasional, but practically an invariable accompaniment
of the use of explosiveiS in the mines of the Rand, and
that nitrous fumes are also not infrequently present in
dangerous amounts. Where definite partial burning of
the explosive takes place (the so-called “ soft shot ”),
the amount of carbon monoxide and of nitrous fumes is
proportionately increased. Imperfect detonation may
be caused by the use of detonators, which are not
powerful enough for the amount of explosive used, or
which have become deteriorated by damp through
temporary storage underground, or by a disproportion
between burden and charge, or by faulty methods of
charging and firing. Finally, when the explosive is not
detonated at all, but is accidentally set on fire and burns,
large quantities of these dangerous gases are evolved.

I know of no evidence that any important amount of
blackdamp is in general found in the mines of the Rand.
In the records of gassing accidents extending over four
years (1904-1907), I could find none which pointed to
vitiation of the air by blackdamp as the cause. How-
ever, accidents due to this cause may occur under
exceptional conditions. In “ gassing ” accidents from
the fumes of explosives, some amount of blackdamp may
sometimes be present also, when the working has lain
idle for more than the usual periods. But the results
of analyses of mine air after blasting show that carbon
dioxide is never present in amounts sufficient to produce
unconsciousness or death by itself. One may safely say
that carbon dioxide taken by itself is never the cause of
fatal accidents in the mines of the Rand. The history
of these accidents, and the results of post mortem
examinations, are also in complete agreement with this
conclusion. On the other hand, this gas is probably not
infrequently present in quantities sufficient to produce
symptoms, and to aggravate or accelerate the effects of
any carbon monoxide present. It is certain that
deficiency of oxygen, combined with excess of carbon
dioxide, may frequently be present in the atmosphere of
close places after blasting in a degree sufficient to extin-
guish the flame of a candle. The warning given by this
occurrence should never be neglected, for although the
vitiation which directly causes it may not in itself be
dangerous, the extinction of lights gives warning of the
probable presence of dangerous quantities of carbon
monoxide also.

There remain, therefore, the two gases, carbon
monoxide and nitrous fumes, as the main active agents
in causing “ gassing ” accidents. The former gas is
practically invariably produced in dangerous quantities
after ordinary blasting, and the latter is also not uncom-
monly present in dangerous amount, especially where
there has been a partial burning of the explosive. One
might expect, as a consequence, that cases of mixed
poisoning by both gases would frequently occur, but in
the great majority of cases one or other type is markedly
predominant. The (Symptoms In each case are quite dis-
tinctive.

Carbon Monoxide Poisoning.

In gassing accidents due to carbon monoxide, those
overcome are frequently already dead when extricated,
or succumb very shortly afterwards. If they survive the
first hour or two, recovery, in my experience, is almost
invariable. There is one feature of carbon monoxide
poisoning which is worth noting, namely, that sudden
exposure to cool fresh air may sometimes greatly inten-
sify the symptoms, or cause, for example, a recurrence
, of unconsciousness after partial recovery. This fact
should be kept in mind in treating these cases.

When a man poisoned by carbon monoxide is removed
to fresh air, the combination of that gas with haemo-
globin gradually gives way in the presence of air, especi-
ally if the latter contains an excess of oxygen, such as
can be supplied by the oxygen cylinder. The carbon

* From an article published in the Medical Journal of
South Africa.

monoxide passes off in the expired air, oxyhaemoglobin
is gradually re-formed, consciousness returns, and the
affected man recovers. The displacement of carbon
monoxide, however, is slower than its absorption. The
time taken depends on the original degree of saturation,
and, other things being equal, is probably also increased
by a longer duration of exposure. Experience shows
that even in bad cases half-an-hour or an hour, less or
more, will generally suffice to get rid of enough of the
gas to place the patient beyond immediate danger. The
results of direct and experimental spectroscopic observa-
tions regarding the length of time, during which the
presence of carbonyheemoglobin may be detected in the
blood of the living after exposure, vary considerably.
Usually in six or eight hours practically all the carbon
monoxide is eliminated. The maximum limit is pro-
bably considerably longer than this, but all evidence
shows that the remote effects of carbon monoxide poison-
ing cannot be ascribed to prolonged retention of the gas
in the blood.

In my experience of carbon monoxide poisoning, if a
man is extricated alive, and promptly treated, he usually
recovers. If death does not take place within an hour
or two, recovery is almost invariable, and takes place
within a comparatively short time. Serious after effects
are, I think, rare in cases of carbon monoxide poisoning
as they occur on the Rand. Severe headache, greatly
aggravated by movement, and lasting for perhaps 12 or
24 hours, sometimes for several days, is common and
characteristic. Vomiting also is common, and epigastric
pain is not infrequent. These symptoms are observed
when the affected man has been brought to fresh air. I
have seen occasionally marked temporary excitement
and mental confusion or exaltation, and even definite
epileptiform convulsions during the stage of recovery.
Drowsiness, giddiness, and slight breathlessness on exer-
tion, and irregularity of the pulse, may also persist for
some days. Bronchial irritation and cough may be
observed, but in some cases this may be due to coinci-
dent slight nitrous fumes poisoning. Idiosyncrasy
counts for a good deal in susceptibility to carbon
monoxide. Alcoholics appear to stand “ gassing ”
badly, so, naturally, do those affected by miners’
phthisis. Occasionally I have heard sufferers from
miners’ phthisis state that they have never been the
same after having been “ gassed,” and they have attri-
buted the commencement of their breakdown to this
cause.

But the long train of serious after effects which have
been repeatedly observed in England and elsewhere in
cases of carbon monoxide poisoning after colliery explo-
sions or fires, or after poisoning by the gas from other
sources, is, in my experience, comparatively incon-
spicuous on the Rand.

Pneumonia is a not uncommon'cause of death after
carbon monoxide poisoning. The type is usually lobar
and extensive, sometimes broncho-pneumonic. The
condition develops on the second or third day, some-
times later, and the disease commonly runs a rapid
course, the patient often dying after two or three days’
illness. I mention these facts in order to differentiate
such cases from those of nitrous fumes poisoning, iiy
which the acute respiratory symptoms always develop
within 12 hours. Personally, I do not recollect any
case.admitted to hospital from carbon monoxide poison-
ing, in which lobar pneumonia has developed within a
few days, but I should be glad to hear the experience of
others. It is probable that such cases do occur from
time to time, but I do not think they are at all common.
In one instance in the records, the mining inspector held
that the death of a native, who had been admitted to a
mine hospital suffering from “ gassing,” and who, after
three days, developed pneumonia, and died on the 10th
day after the accident, was due to the accident. The
point is of medico-legal interest. Acute oedema, of the
lungs has also been described.

If I am right in considering that serious after effects
are comparatively infrequent on the Rand, I can only
conclude that an important factor in producing them is
duration of exposure. With us the exposure is short
and sharp. After colliery explosions exposure is often
prolonged, and poisoning is more gradual. At the great
explosion, followed by a serious fire, which occurred at
Senghenydd in October 1913, 440 men were killed, and
18 were rescued alive, and survived, after an exposure
to afterdamp for 20 hours.

Chronic carbon monoxide poisoning occupies a con-
siderable space in the literature of the subject. The
observed cases of this condition are numerous and well
authenticated. On the other hand, there is equally
valid evidence of the acquisition in many cases of
tolerance to repeated small doses of the gas. The point
is of practical interest, since intermittent exposure to
small amounts of carbon monoxide may not infrequently
take place underground, for example, in persons waiting
to be hauled up the shaft after blasting, or when the
ventilation of workings in which blasting has taken place
is inadequately carried out. The question of protecting
waiting places from the access of dust and blasting
fumes is now receiving attention.

Nitrous Fumes Poisoning.

We may turn now to the consideration of the
symptoms of cases of poisoning caused by the irritant
acid fumes, commonly known as nitrous fumes. The
gas is intensely poisonous, and of all mine gases it is the
most treacherous. We do not know the downward limit
of its toxicity. Exposure to as little as 0-05 per cent,
of nitric oxide for half-an-hour was found by Haldane to
cause death in mice after about 24 hours, with the
typical sequence of symptoms, and the symptoms were
the same whether nitric oxide or the fumes of burning
dynamite were added to the air. Half of the amount
mentioned is the highest figure (0-026 per cent, reckoned
as N02) found by Mann in mine air after blasting, but
the presence of the gas in poisonous amounts is pro-
bably not so very uncommon in ordinary blasting prac-