London Labour and the London Poor, Vol. 2

by Henry Mayhew

“The ordinary smoke,” Professor Faraday said, in his examination before the Committee, “is the visible black part of the products, the unburnt portions of the carbon. If you prevent the production of carbonic oxide or carbonic acid, you increase the production of smoke. You must with coal fuel either have carbonic acid or oxide, or else black smoke.

“Which is the least noxious?” he was asked, and answered, “As far as regards health, carbonic acid and carbonic oxide are most noxious to health; but it is not so much a question of health as of cleanliness and comfort, because I believe that this town is as healthy as other places where there are not these fires.

“It is partly the impure coal gas evolved after the fresh charge of coal which originates the smokes, when not properly supplied with air; but it is a very mixed question. When a fresh charge of coal is put upon the fire, a great quantity of evaporable matter, which would be called impure coal gas according to the language of the question, is produced; and as that matter travels on in the heated place, if there be a sufficient supply of air, both the hydrogen and the carbon are entirely burnt. But if there be an insufficient supply of air, the hydrogen is taken possession of first, and the carbon is set free in its black and solid form; and if that goes into the cool part of the chimney before fresh air gets to it, that carbon is so carried out into the atmosphere and is the smoke in question. Generally speaking, the great rush of smoke is when coal is first put on the fire; and that from the want of a sufficient supply of oxygen at the right time, because the carbon is cooled so low as not to take fire.”

This eminent chemist stated also that there was no difference in the ultimate chemical effect upon the air between a wood fire and a coal fire, but with wood there was not so much smoke set free in the heated place, which caused a difference in the gaseous products of wood combustion and of coal combustion. He thought that perhaps wood was the fuel which would be most favourable to health as affecting the atmosphere, inasmuch as it produced more water, and less carbonic acid, as the product of combustion.

What may be called the peculiarities of a smoky and sooty atmosphere are of course more strongly developed in London than elsewhere, as the following curious statements show:—

Dr. Reid, in describing metropolitan smoke, spoke of “those black portions of soot that every one is familiar with, which annoy us, for instance, at the Houses of Parliament to such an extent that I have been under the necessity of putting up a veil, about 40 feet long and 12 feet deep, on which, on a single evening, taking the worst kind of weather for the production of soot, we can count occasionally 200,000 visible portions of soot excluded at a single sitting. We count with the naked eye the number of pieces entangled upon a square inch. I have examined the amount deposited on different occasions in different parts of London at the tops of some houses; and on one occasion at the Horse Guards the amount of soot deposited was so great, that it formed a complete and continuous film, so that when I walked upon it I saw the impression of my foot left as distinctly on that occasion as when snow lies upon the ground. The film was exceedingly thin, but I could discover no want of continuity. On other occasions I have noticed in London that the quantity that escapes into individual houses is so great that in a single night I have observed a mixture of soot and of hoar frost collecting at the edge of the door, and forming a stripe three-quarters of an inch in breadth, and bearing an exact resemblance to a pepper and salt grey cloth. Those that I refer to are extreme occasions.”

Mr. Booth mentioned, that one of the gardeners of the Botanic Garden in the Regent’s-park, could tell the number of days sheep had been in the park from the blackness of their wool, its oleaginous power retaining the black.

Dr. Ure informed the Committee that a column of smoke might be seen extending in different directions round London, according to the way of the wind, for a distance of from 20 to 30 miles; and that Sir William Herschel had told him that when the wind blew from London he could not use his great telescope at Slough.

It was stated, moreover, that when a respirator is washed, the water is rendered dirty by the particles of soot adhering to the wire gauze, and which, but for this, would have entered the mouth.

Professor Brande said, on the subject of the public health being affected by smoke, “I cannot say that my opinion is that smoke produces any unhealthiness in London; it is a great nuisance certainly; but I do not think we have any good evidence that it produces disease of any kind.”