while, instead of the present wasteful method of quenching the red hot coke, it will be shot direct into the generator of the water gas plant, and the water gas carbureted with the benzene hydrocarbons derived from the smoke of the blast furnace and coke oven, or from the creosote oil of the tar distiller, by the process foreshadowed in the concluding sentences of my last lecture.  It will then be mixed with the gas from the retorts, and will supply a far higher illuminant than we at present possess.  In parts of the United Kingdom, such as South Wales, where gas coal is dear, and anthracite and bastard coals are cheap, water gas highly carbureted will entirely supplant coal gas, with a saving of fifty per cent. on the prices now existing in those districts.  While these changes have been going on, and while improved methods of manufacture have been tending to the cheapening of gas, it will have been steadily growing in public favor as a fuel; and if in years to come the generation of electricity should have been so cheapened as to allow it to successfully compete with gas as an illuminant, the gas works will still be found as busy as of yore, the holder of gas shares as contented as to-day; for with a desire for a purer atmosphere and a white mist instead of a yellow fog, gas will have largely supplanted coal as a fuel, and gas stoves, properly ventilated and free from the reproaches I have hurled at them to-night, will burn a gas far higher in its heating power, far better in its power of bearing illuminating hydrocarbons, and free from poisonous constituents.

When the demand for it arises, hydrogen gas can be made as cheaply as water gas itself, and when time is ripe for a fuel gas for use in the house, it is hydrogen and not water gas which will form its basis.  With carbureted water gas and 20 per cent. of carbon monoxide we are still below the limit of danger, but a pure water gas with over 40 per cent. of the same insidious element of danger will never be tolerated in our households.  Already a patent has been taken by Messrs. Crookes and Ricarde-Seaver for purifying water gas from carbon monoxide, and converting it mainly into hydrogen by passing it at a high temperature through a mixture of lime and soda lime, a process which is chemically perfect, as the most expensive portion of the material used could be recovered; but in the present state of the labor market it is not practical, as for the making of every 100,000 cubic feet of gas, fifteen tons of material would have to be handled, the cost of labor alone being sufficient to prevent its being adopted; moreover, hydrogen can be made far cheaper directly.

From the earliest days of gas making, the manufacture of hydrogen by the passage of steam over red-hot iron has been over and over again mooted, and attempted on a large scale, but several factors have combined to render it futile.