Science.

Wairarapa Standard, Volume XX, Issue 2090, 8 July 1887, Page 2 (Supplement)

Science.

Garbage. The apparent purpose of chemistry, so often realized in the last thirty or forty years, is that nothing shall be wasted, but the solution of the vexed question “ what to do with garbage ” appears thus far to have escaped the notice of the chemists. The very best disposition of it would be for evqry family to burn its own in the kitchen fire, but there are many housekeepers who object to this. They say it causes unpleasant odon through the bouse. The writer is nnable to confirm this after ten years’ experience. The odor, if any, goes up the chimney, as all bad odors should. But the fact remains that in cities there will always be great numbers of housekeepers who want such work done for them at public expense. The cremation of garbage is just now attracting attention. This would be excellent as compared with converting it into unwholesome meat and milk, but there would be nothing recovered except the ash, which might have some slight value for fertilizing. The writer has for some months been considering a plan for destructive distillation of garbage, which for the purposes of this article is understood to mean waste food products, animal and vegetable. It may be premised that it is as much the duty of cities to disinfect the sewers as to clean the streets or extinguish fires ; therefore, as this will involve only a small extra expense, let the necessary works be erected near the bead of one of the sewers and lay a pipe—say six inches—from the sewer to the grating of the furnace, which should be inclosed in such a way that the draft for the fire would come from the sewer instead of the surrounding air. Having a high chimney to secure free combustion, this would withdraw the sewer gas and render it innoxious by burning. Let me say in passing that it would be worth while for the authorities of a city having sewers and factories with high chimneys to connect them in this way to aid thus far in disinfection. Having our pipe in place, the plan of operation should be about as follows ;

Ist. As there is always more or less melted grease and greasy water in barrels, dump the contents into bins having a slantiug grooved bottom and a gutter on one side by which the liquid portions should be conducted to a vat for treatment.

2nd. When the garbage has drained, transfer it to a cylinder or cylinders of boiler iron erected over the furnace; apply beat and through a faucet at the bottom draw off the further accumulation of melted grease. 3rd. When this is abont done introduce a quantity of quicklime, which, in contact with the organic matter, will generate gaseous ammonia. This should be washed and collected in the usual way, be purified and concentrated by a subsequent distillation, heating by a steam coil, 4tb. When ammonia gas is no longer evolved and as the mass acquires a higher temperature, becoming carbonized, the evolution of illuminating gas will begin. This should be conducted through a washer into a suitable receiver. sth. When this is finished there will remain in the cylinder or retort a coke which can probably be used as fuel for further operations.

6th. The ash from this might possibly contain enough potash to pay for lixiviation. This could readily be determined by analysis. 7th. The melted grease and water should be pumped into a boiling pan placed over the fire, strained off and allowed to cool. Then collect the solid fat and purify by boiling and cooling again with clean water once or twice and finally utilize in making axle grease or in some other commercial way that should insure that it would never touch the human skin.

1 believe the plan here outlined would be feasible, and by some aid from the city would in time yield a profit. It would not be difficult to prepare working designs for the necessary plant and by hiring some idle factory the experiment could be tried on a practical scale for £250 or less.

Electrical Searches for Bullets.— When President Oartield was slowly dying at Elberon, and the attending surgeons were locating the fatal bullet in spots clear away from where, after death, it was discovered, an electric apparatus was qpnstructed by Prof. Graham Bell for the purpose of finding the bit of lead. The failure was ridiculed, much to the chagrin of Bell and the doctors. The discovery has since been made that Garfield lay on a metallic mattress, which frustrated the electricity'. Now, under the sanction of the New York Academy of Medicine, a machine has been constructed and tested. The machine consists of a battery, coils, and other familiar telegraphic devices, but principally of a thin steel probe connected with the wires in a manner invented by Bell. The surface of the patient over an imbedded bullet was cocained, so as to deprive it of all feeling. Then the probe was thrust in. As the end of the steel came within six inches of the bullet, the surgeon with his ear to a telephonic cap, heard a humming sound, which grew louder as the metal was approached. The flesh was jabbed a number of times, and the trial was regarded as a success. Later, a war veteran submitted to a search for a bullet that had entered his chest and remained somewhere in him for twenty years. The needle hummed its way to the lead’s hiding place and it was removed. Dr. John H. Girdner. who operated the instrument, said that its use would have saved Garfield’s life in all probability. Manufacture of Paper Pipes.— These pipes, ns manufactured in Germany, are made of hemp paper, not rough felt paper, and asphalt. The mode of manufacturing them is the following : The J>ot paper mass is wound around a roller by machinery, and when the desired thickness has been attained it is pressed until it gradually cools and hardens. The durability of these paper pipes is said to be established beyond reach of doubt, while to cut the asphalted paper stuff is like cutting hard wood. The pipes are of a lava-like black, and at the first glance they look like asphalt, being smooth within and rough without. For water, gas, subterranean telegraph wires, telephone conductors, etc., the pipes are reported to serve admirably. Sandpaper.— Sandpaper is at present made with powdered glass Instead of sand. Glass is readily pulverised by heating it redhot and throwing it into water, and finishing Ihe powdering in an iron mortar. By the use of sieves of different sizes of mesh, the powder can be separated into various grades, from the finest dust to very coarse; and these should be kept separate. A strong paper is tacked down and covered with a strong size of glue, and the 'surface covered with powdered glass of the desired fineness. When the glue is dry the surplus glass is shaken or brushed off. Muslin is better than paper, and lasts much longer in use.

Tarred Floors —Some months ago the floon of many Austrian garrisons were pamted with tar, and the results have proved so uniformly advantageous that the method is becoming greatly extended in its application. The collection of dust in cracks is thus prevented, and a consequent diminution in diseases of the eye has been noted. Cleansing of the rooms has been greatly facilitated, and the parasites are almost completely excluded. The coating of tar is inexpensive, requires renewal but once a year, and presents but one disadvantage, namely, its sombre color.