Scientific Notes

A Germán mixture for the removal of ink consista of alum. amber, sulphur and saltpetre, one part of each. A concentrated beam of electric light carried seven miles has furnished suüicient light to read by. Gun cotton is insoluble in water, being unaffected even by long soaking. Strong sulphuric acid dissolves it with some difflculty. Our consul at Euatan, Honduras, writes home about a new silk grass which he thinks is better than hemp or flax, and about the tunal tree which produces a gum better than India rubber. The loudness of sound produced by a soundmg body is augmented by bringing the body into the neighborhood of a column of air capable of vibrating in unisón with it. Hay, like most vegetable productï, contains much material which is soluble in water. On this material its nutritive value depends, and ita removal by dampness seriously injures the erop. Steel tools should never be heated, either for forging or tempering, in a fresh coal flre unless it becharcoal. If coke is not at hand the fire should be allowed to burn until the gas Is burned out of the coal before the steel is introduced. Stalactiteá are formed by rain water percolating through the roofs of caverns, and by its carbonic acid dissolving the carbonate of lime in the rock. In dripping from the roof it gives up a portion of its carbonic acid to the air, and the carbonate of lime, no longer held in solution, is deposited. By securing variety in temperature, through planting oysters in different depths of water, as practiced in Connecticut, the Scientiflc American says oystei's can be obtained in a üt condition for the table every week in the year. The greater the heat the earlier the oyster will spawn. Those in the deeper and colder water f eel the heat later and spawn later. Some portion of the oyster field, so to speak, will therefore be ready for harvesting at all times. From the investigations of Profs. Kedzie, Nessier, Barth, Fleck, and Schmitz it appears that potato sugar contains as impurities sulphuric acid, iron sulphate, and lime. lts mostdangerous ingrediënt, however, is a bitter matter which remains after the sugar has passedinto fermentation.and which occasions cold sweats, oppression of the chest, headache, and other dangerous or annoying symptoma. Wines treated with potato sugar are consequently pro tanto poisonous, and the authorities given above question whether it should be permitted to be employed in brewing.