1252

THE COLLIERY GUARDIAN.

June 21, 1918.

many others in Lancashire very iirmiy believed, viz.,
the value oi shale dust or stone dust as a remedy tor
coal dust explosions. That was not an opinion which
rested on a tew test experiments: it had prevailed
for some years, if anybody suffered in consequence
of the use of shale dust, surely those youths who were
throwing handfuls of shale dust on to the sides of the
road ana taking some of it into their lungs, hour after
hour, would have been dead long since, in Lancashire
they were distributing shale dust on the roof and sides
of their roadways right away from the bottom of the
downcast shaft to the bottom of the upcast shaft.
He had been more than once through the operation
and had come out smothered from head to foot as
though he had been through a flour mill, and he had
never been in the slightest degree the worse for the
hours of experience oi inhaling that shale dust. So
he, for one, greatly valued Dr. Haldane's paper, and
he thought that they in Lancashire would be en-
couraged to go on shaie-dusting as the remedy for the
danger of coal dust.

Pit Ponies and Dust.

Mr. C. C. Ellison said he was wondering why
Dr. Haldane had not said anything to them about
the effect of coal dust on the ponies in the mines.
They probably breathed more dust than anybody else,
because they generally stirred up the dust themselves,
and not only that, but they spent four times as much
time in the pit as any man who ever went into it.
They were living down there. It would be very inter-
esting to know if any examination had been made of
the lungs of the ponies.

Sir Henry Cunynghame said it had been done, and
it was found that it did no harm.

Mr. Ellison said it was well known how very much
better the ponies had fed since the dust had been
extracted from their food, which in the old days had
not been done. There was also another question. He
thought it was generally agreed that the men who
got most dust into their lungs were the men who
were working on the screens, working in connection
with grinding machinery. They probably breathed an
atmosphere 100 or 200 per cent, worse than that which
was breathed at the coal face or in the workings. It
had always surprised him how very few epidemics
there were in the mine amongst the men or amongst
the ponies. He thought they all knew what a high
value the coal had from a disinfecting point of view.
The question was whether the breathing of that dust
did not help in many ways to kill other germs, and
so make the men healthy in directions other than with
regard to the lungs. He would very much like Dr.
Haldane to tell them what his experience in that direc-
tion had been. Even if Dr. Haldane had not made a
study of it, he was quite sure that from his very keen
observation in connection with mines he had probably
got something not only instructive, but, he should
imagine, something very amusing to tell them from
the practical observation which he made in his travels.
He had noticed in the figures which Dr. Haldane
gave that at 200 yards away from the face there was
practically the same percentage of stone dust on the
roof as there was on the floor—50-7 per cent, on the
former, as again 51-0 per cent, on the latter. That
struck him as being rather peculiar, because he had
generally found coal dust to be lighter than stone
dust.

Mr. Richardson (former president of the South
African Mining and Metallurgical Society) said he
had read Dr. Haldane’s paper, and had listened to
the discussion, but as he had left the Transvaal several
years ago, he was afraid he could not tell them much
about the present conditions underground there. All
he could say was that every precaution was taken by
means of atomisers and sprays and so forth to lay
all the dust. Another great innovation, which had
produced most excellent results, was the organisation
of the mines so that only one shift would be working
underground, and that no blasting would take place
in the mine while that shift was working there. The
blasting all took place after the shift had come to
the surface, and that measure had proved to be of
great benefit, for the simple reason that the most
deleterious form of dust seemed to be the very fine
dust created by the rending effect on the rock of the
high explosives used in blasting. The dust produced
by rock drills did not seem to have done so much
harm as the very fine impalpable dust which was not
always laid by atomisers, and which went through
any respirator that had so far been invented.

Coal Districts as Sanatoria.

Mr. D. M. Mowat said that Dr. Smeeth had antici-
pated a remark which he was going to make as to
the possible application of coal dust to the prevention
of phthisis. He had had a visit last week from a
man from Inverness, a wood merchant. It was his
first visit to Coatbridge, which was rather a smoky
place, more smoky than London a good deal. He
(Mr. Mowat) said, “ What do you think of our sana-
torium?” His visitor looked out of the window,
which was in such a position that the sanatorium was
looking pretty black, and said, 11 That is not the sort
of place in which we build sanatoria; we build them
on the hills.” He realised while Dr. Haldane was
reading the paper that that was all wrong. People
were taken away to a place where there was no chance
of getting a particle of dust, the healthy, remedial
dust which would do some good to a man’s lungs.
Was not that a mistake? Might it not be a good thing
to have in a sanatorium some place where a man could
be introduced into coal dust of the proper amount,
that dust being — as might perhaps be proved by
the results of experiments on guinea-pigs—of help
in getting rid of the tubercle bacilli? He was very
pleased to hear the testimony of Sir Henry Cunyng-
hame as to what coalowners were prepared to do after
they were convinced. The whole point was that some
of them were difficult to convince, and he believed
that on several occasions they had been difficult to
convince. He must say that he had that day received
more valuable testimony of the utility of stone dust

than he had ever received before. He thought there
was a good deal of truth in what they had been told
about what had been known of various things, but
he did not believe it was at all a good thing to run
down scientific investigations. He would be the last
to do so, because he knew there was not the slightest
doubt that a person setting out on a distinct line of
investigation might not reach the goal, whereas a
person going on a widespread investigation, not know-
ing where the way led him, might at the end of one
of the roads reach a goal which was of very great
value. He, for one, would not in any way seek to
minimise the value to be put upon scientific investi-
gation. Where the difficulty arose, and where the
difference between coalowners and the Public Depart-
ments came in, was as to the proper application. He
would give an instance of that. He had no personal
interest in it, and could therefore speak with greater
freedom. There was an order issued in the present
year, and one of the regulations applied to the break-
ing up of a piece of ganister. It was to be carefully
placed upon the floor, covered over with a piece of
wet brattice cloth—which one could not get for love
or money—and then worked with a hammer on the
outside, "so that no particle of ganister dust might
escape. That might be a very valuable precaution,
but having regard to the state of things which
existed, the scarcity of men, the scarcity of material,
and the scarcity of the people who made brattice cloth,
and the fact that thousands of men were dying for
us every day, he thought that that might well have
been held back until after the war.

Advantages of Science.

The Chairman (Sir Wm. Garforth) said he would
like to make a few remarks in connection with what
Col. Blackett had said. Col. Blackett seemed to
describe what had taken place in connection with coal
dust for more than a century. He wished to remind
the members that the practical work which was done
by Mr. Buddle, one of those eminent North of England
men, was supplemented by the investigations made
by Prof. Faraday and Sir Charles Lamb. Afterwards
matters went on, still a great number of lives being
lost, up to the commencement of this century. Then
they had the investigation following the Altofts ex-
plosion, and it was then noticed that coal dust had
produced great destruction on the various roads, and
that no destruction was found on the stone dust roads.
That was brought out in the enquiry of the Coal Dust
Commission in 1891, but no experiments were made,
although they were recommended, until they were
recommended again in 1906 or 1907 by the Royal Com-
mission over which Sir Henry Cunynghame presided.
Knowing that Col. Blackett had done everything he
could to introduce scientific knowledge to the insti-
tution, he knew that what he said was not really what
he desired and what they knew to be right, because
all those different practical experiments had been
supported by science. For instance, after the Royal
Commission asked coalowners to provide the means to
conduct some practical experiments, they did so, with
the result that many people who had come to Altofts
disbelieving that coal dust was explosive, went away
convinced that it was. Therefore he considered that
the Altofts experiments were on a scientific basis, and
that they bore out the practical results. Then the
microscopical investigation showed that the shale dust,
blue shale fine, collected after the Altofts explosion,
when exposed to the action of flame turned a dull red.
There again one saw the advantage of science. After-
wards experiments proved that stone dust ex-
tinguished a flame of about 170 ft., due to a coal dust
explosion, bearing out the practical results, or rather
the practical results were proved by the scientific in-
vestigations. Then when they were told that there
was no room for further dust down the mine, he
admitted the practical results showed that there was
no more dust in the mine that there was before, but
one difference was that the dirt or dust was in large
or small pieces, whilst the stone dust taken out of
the mine was so fine that it was raised as a cloud
in the air. With regard to the point which had been
raised by Sir Henry Hall that if one stone-dusted
the roads, and the stone dust became covered with
coal dust, the danger was as before. Sir Henry, as
Col. Blackett had pointed out, seemed to have for-
gotten that the pockets and interstices of the mine
were filled with dust. Fortunately the stone dust
was so heavy that it allowed for a velocity of air
far in excess of the abnormal quantity required to
ventilate a coal mine, and was not itself moved until
the coal dust had been blown out from the roadway;
that was to say, a velocity of air of 1,000 or even
1,200 ft. did not remove the coal dust, but a velocity
of 1,500 or 1,600 ft. was sufficient to take away the
coal dust, whereas the stone dust still remained till
the velocity attained 2,600 ft. One could always have
sufficient ventilation before either the coal dust or the
stone dust blew away. Some time ago the Miners’
Federation appointed some members to visit Altofts,
and they were fully satisfied, from the experiments
which they saw, that one could get all the ventilation
required for a mine without interfering with the coal
dust or the stone dust. Sir Henry Hall had also
raised the question of how the traffic would be inter-
fered with, and the transport, and other matters of
that kind. The stone-dusting question had not been
helped forward by finding fault, without giving some
kind of remedy. He could only say that, after using stone
dust for the last 9| years, they found no inconvenience
with the traffic, the transport, or the ventilation.
He believed that those scientific investigations which
had taken place had helped them very much to see that,
from whatever standpoint one looked at the question
of stone-dusting with a view of preventing colliery
explosions, the obstacle which had been suggested in
the early stages had been removed. He sincerely
hoped that Dr. Haldane and other scientific members
connected with the institution would continue their
investigations and show that they were on the right
track of something which would lead to beneficial
results in connection with metalliferous mining in
other countries as well as in Cornwall.

Sir Wm. Atkinson, I.S.O. (Tintern), in a written
communication, stated that it would appear, from
Dr. Haldane’s paper, that the physiological action and
effects of the inhalation of different sorts of dusts were
not yet thoroughly understood. There was, however,
so far no evidence that the use of shale dust, as applied
for making coal dust inexplosible, was injurious to
health, and it would be unfortunate if that uncon-
firmed fear were allowed to prevent or delay the appli-
cation of what appeared to be a hopeful method of
preventing or limiting such devestating explosions as
had occurred in the past, the provisions of the present
Mines Act, until supplemented by regulations, being
quie inadequate for the purpose. In any case, the risk
to health, if any, need only affect a small proportion
of miners, viz., those engaged in distributing the stone
dust and those employed on the roads where the dust
was used. Stone-dusting had now been practised in
some mines for several years, and he would suggest
that a medical enquiry should be instituted as to the
hygienic effect on the men most exposed to the inhala-
tion of stone dust in such mines.

Dr. Haldane, in reply, said that he thought Sir
Henry Cunynghame just hit the nail on the head as
to what the real function of medicine was when he
said that what one could do in the way of helping the
body was only to assist Nature. If a man’s lungs
were injured by inflammation the doctor could do
absolutely nothing to restore the structure; but what
the doctor could do was to study how Nature mended
those things and then to study, beyond that, how he
could help Nature in the process. Stone-dusting was
a very good instance of the sort, and was, he thought,
typical of what medicine could hope to do. No medical
or surgical skill could extract those dust particles out
of the lungs when once they were there, but one could
study how Nature got rid of them, and then one could
give Nature a leg-up by putting in some other dust
which would help things on. Medicine had first to
study how Nature did the thing, how Nature healed
and mended things, and then it could help. As to
Sir Henry Hall’s communication, there was one thing
he wanted to mention. Sir Henry Hall pointed out
that when one stone-dusted a mine after a short while
one would find on the top of the stone-dust a layer of
dark-coloured or black dust, which he assumed—he
(Dr. Haldane) believed quite wrongly—to be pure coal
dust. If one examined that dust, although it was
dark in colour, one usually found there was 70 per
cent, or so of stone dust in it; it was quite an inex-
plosive stuff, and even if it were explosive it would
not matter; any violent shock like blasting would stir
up a whole lot of dust.

Sir Henry Cunynghame said they had tried that
very experiment, in the experimental gallery, for the
purpose of finding that out, as Dr. Haldane would
remember. The exact point was tried repeatedly.
They had tried putting pure coal dust on the top of
the stone dust; and they had then stirred the whole
thing up together.

Colour no Criterion.

Dr. Haldane said the point he wished particularly
to make was that the black dust one saw in a mine,
which had collected again after it had been stone-
dusted, was not pure coal dust at all. There was the
double point. One must check the composition of the
black dust by analysis. At Bentley the black dust
round the face was analysed and found to contain over
50 per cent, of stone dust before stone-dusting had
been begun there. Replying to Mr. C. C. Ellison,
he said it was not the ash from the cial, but an admix-
ture of stone in filling coal and cleaning it generally.
There was a lot of pure coal dust, but it got so much
mixed with the stone that even the finest of it was
over 50 per cent, stone dust which could not have
exploded, and they had not had any fear in that mine
of an explosion passing round the face. He would
remind Sir Henry Cunynghame that they had had
elaborate evidence about it—because the mine was
prosecuted by the Home Office—elaborate evidence as
to the composition of the dust all over the mine; but,
unfortunately, the Home Office had run away from
that part of their case, and the evidence had not come
eut in court. But still, it was not found to be lost
time afterwards. It was a pitfail. Dr. Collis’s com-
munication was a very interesting one. Dr. Collis had
done a great deal of very valuable work on that sub-
ject. He thought that one of the most valuable
scientific points was his investigation of miners’
phthisis amongst flint knappers. He did not suppose
the amount of silica they breathed was one-tenth of
what a miner breathed in the course of his ordinary
work, but it was pure silica, and it was very fine.
Practically every one of those men, or very nearly
the whole of them, died of miners’ phthisis. The
statistics were very striking. There were very few
of those people left. Phthisis mortality was enor-
mous among them, or had been. Then Dr. Collis and
Dr. Smeeth had raised the question in a much more
definite form. Attention was drawn to the difference
between the effects of granite dust and those of stone
dust, and Dr. Smeeth had put it very distinctly that
in granite there was more silica, but not more quartz,
than there was in shale dust. Yet granite dust was
dangerous; it was granite dust which did the harm
in Cornish mines. Practically the mining was in
granite, and the dust was granite dust, and there
was a great deal of silicate in the dust. Granite was
composed of crystals of quartz, of felspar, and of mica,
all crystalline; they were not in the amorphous form
at all. He thought the probability was that both the
felspar and the mica were more or less dangerous dusts
as well as the quartz. At any rate they were solid
crystalline; the dust was in a solid crystalline form,
and it had no property of absorbing things into it.
It was a solid crystalline structure. In reply to a
remark by Dr. Smeeth, Dr. Haldane said that if the
Kolar stuff were equally crystalline, it presented a
difficulty. The Cripple Creek stuff was not—to look
at; it was a very amorphous-looking stuff. So far
as he had gone with the work, he would say that
the difference depended upon the physical rather than