The Romance of Modern Chemistry

PRODUCTION OF LIGHT AND HEAT this is that the chimney draught sucks the air right through the fuel, which is thereby fed more perfectly with the oxygen it so badly needs. If the newspaper were not there, the bulk of the air which is drawn up the chimney would come in through the upper part of the grate front, without passing through the fuel. The village blacksmith, too, when he makes his bellows roar, is in quest of more rapid combustion, and consequently more intense heat. Imperfect combustion is responsible for the smoke that hangs like a pall over so many of our large cities. We in England insist on having the cheery but unscientific open fireplace, with the result that the fuel is imperfectly burned, and our chimneys pour a constant stream of smoke into the atmosphere. Smoke is charged not only with finely-divided carbon and soot, but also with oily and tarry vapour, whereas if there were perfect combustion nothing but invisible gases would leave the chimney. Just imagine what that would mean ! Apart from the saving in fuel, we should never require the services of the chimney sweep, and we should be spared many of the grimy fogs which come, especially in London, to clog our breathing organs and to depress our spirits. Why should it be so uneconomical and unscientific to bum coal in such open fireplaces as are common in England ? The key to the answer lies in the fact that when coal is heated it first gives off a quantity of in- flammable gas, and it is really this gas which bums when we put coal on a fire. But unfortunately in our open fires the fresh coal is put on the top, so that the gas which comes out of the coal as it gets warmed up is in a part of the fire where the supply of oxygen is limited. Not only has a considerable portion of the oxygen been used 110