Page:Popular Science Monthly Volume 27.djvu/232

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THE POPULAR SCIENCE MONTHLY.

The charge of a puddling-furnace, consisting of 500 pounds of pig-metal and eighty pounds of "fix," produces with coal-fuel 490 to 500 pounds of iron. With gas for fuel, it is claimed that the same charge will yield 520 to 530 pounds of iron. In an iron-mill of thirty furnaces, running eight heats each for twenty-four hours, this would make a difference in favor of the gas of, say, 8 X 30 X 25 = 6,000 pounds of iron per day. This is an important item of itself, leaving out the cost of firing with coal and hauling ashes.

For generating steam in large establishments, one man will attend a battery of twelve or twenty boilers, using gas as fuel, keep the pressure uniform, and have the fire-room clean as a parlor. For burning brick and earthenware, gas offers the double advantage of freedom from smoke and a uniform heat. The use of gas in public bakeries promises the abolition of the ash-box and its accumulation of miscellaneous filth, which is said to often impregnate the "sponge" with impurities.

In short, the advantages of natural gas as a fuel are so obvious to those who have given it a trial, that the prediction is made that, should the supply fail, many who are now using it will never return to the consumption of crude coal in factories, but, if necessary, convert it or petroleum into gas at their own works.

It seems, indeed, that, until we shall have acquired the wisdom enabling us to conserve and concentrate the heat of the sun, gas must be the fuel of the future.

 

USE OF SULPHUROUS DISINFECTANTS.
By GASTON TISSANDIER.

AMONG the most convenient and efficacious substances to be used for purposes of disinfection are sulphurous acid and bisulphide of carbon. The question of the merits of these substances and the advantages of using them was recently considered, in the "Journal de Pharmacie et de Chimie," by M. Alfred Riche, who said: "M. Dujardin-Beaumetz recently requested the concurrence of MM. Pasteur and Roux in instituting new experiments on the value of disinfectants, and has just published the results of the same in the 'Bulletin' of the Academy of Medicine. Two rooms of about a hundred cubic metres capacity were selected in the wooden barracks attached to the hôpital Cochin. The walls of these rooms, made of jointed planks, gave passage to the air through numerous cracks, although the precaution had been taken of stopping the larger ones with paper. Each of the rooms was furnished with a bed, the usual furniture, and cloths of different colors. Bromine, chlorine, and sulphate of nitrosyle were successively rejected. Three sources of sulphurous acid were experi-