MECHANICS AND USEFUL ARTS. 103 



cine; while it is difficult to imagine a case m which a person could pom- out 

 and take the whole contents of one of these bottles in mistake for something: 



o 



else. To illustrate the manner in which the new bottle acts, in comparison 

 with ordinary ones, it may be mentioned that not more than a teaspoonful 

 would come out in the same time that an ordinary vial would take to dis- 

 charge its entire contents. A person being about to take a wrong medi- 

 cine, say laudanum, contained in this new bottle, on proceeding to pour it 

 out, would be struck by finding that instead of the whole draught having 

 run into the wine-glass, as usual, merely a teaspoonful would have left the 

 bottle; this would naturally lead to an examination of the label, and the 

 consequent discovery of the error. Although to empty even a two-ounce 

 bottle Avould tire the hand and arm of the holder, yet when only the pro-, 

 posed dose is sought to be withdrawn, the patience is not taxed in the slight- 

 est degree. This invention recommends itself to general notice on account 

 of its thoroughly practical character. 



INDUSTRIAL APPLICATION OF TALC. 



A new application of the natural silicate of magnesia, known as steatite, 

 or talc, has recently been made in France; namely, the manufacture of but- 

 tons, and even very handsome cameos, provided that, after its fabrication, 

 the object be exposed during several hours to a white heat. By this strong 

 calcination the steatite acquires sufficient hardness to strike fire with steel, 

 ancl to resist the hardest file. It can be polished with emery, tripoli, and 

 putty-powder, and may likewise be colored by different organic and mineral 

 substances; thus, chloride of gold dyes it purple, nitrate of silver produces 

 a black. By exposing the object to the deoxidizing blow-pipe flame, the 

 brilliancy of the colors is much heightened. 



SUBSTITUTE FOR LINSEED DRYING OIL. 



Joseph "W. Harmon, of Elizabethtown, X. J., has recently patented the 

 following composition : He takes the residuum of the stills of candle fac- 

 tories as the important basis of his compound, which consists of certain 

 products from palm-oil, lard, tallow, or other greasy matters remaining after 

 the stearic acid has been taken off. To one gallon of this residuum is added 

 one gallon, more or less, of rosin-oil, and these are melted together into one 

 homogeneous mass; then three-quarters of a pound of litharge is added, 

 and one pound and a half of umber, together with three pounds fresh slaked 

 lime, and three pounds of oil-cake. The whole mass must be carefully 

 mixed and boiled properly, and, after cooling, it is brought to a proper con- 

 sistency by spirits of turpentine, when a good substitute for linseed drying oil 

 is produced the proportions varying, of course, according to circumstances. 



SULPHURIZED OIL PAINT. 



A sulphurized oil paint has recently been brought to the notice of the 

 Society of British Architects. It is prepared by subjecting eight parts of lin- 

 seed-oil and one part of sulphur to a temperature of 278, in an iron vessel. 

 This paint, when applied to the surface of a building of stone or brick, or to 

 wood-work, with a brush, effectually keeps out the air and moisture, and 

 prevents the deposits of soot and dirt. It is said that it improves the color 

 of stone and brick, as well as preserves them. 



