Home › Miscellaneous Receipts › Brick-Dust Cement

Brick-Dust Cement

Ordinary brick dust, made from hard burned, finelypulverized bricks, and mixed with common lime and sand, is a good substitute for hy draulic cement. The proportions used in general practice are 1 part brick-dust and 1 of lime to 2 of sand, mixed together dry, and tempered with water in the usual way. 6387. Cement for a Crack in a Castiron Pot. If the crack be in the bottom of the pot, drill a hole at each extreme end of the crack, to stop further cracking, plug rivet

6381. Το Keep Gum-Arabic from the holes with copper, and, with fine iron fil- Moulding. Solutions of gum-arabic soon ings saturated with urine, caulk the crack. mould and sour, and finally lose their adhe- This method has been tried on oil-pots on sive property. It is said that sulphate of board whale ships with success. quinine will prevent this, while it imparts no 6388. The Drummond Light. This bad odor of its own. The addition of a solu- brilliant light is produced by directing a tion of a few crystals of this salt to gum-ara- stream of oxygen gas, passing through the bic will prevent the formation of mould quite as effectually as carbolic acid, and by analogy it is safe to suppose that the same salt could be used in writing ink, mucilage, and, possibly, glue. flame of a spirit lamp, upon a small ball of quicklime of about 1 inch in diameter. It gives an intense light; and, placed in the focus of a parabolic mirror, has been distinctly seen at a distance of 60 miles. 6382. Το Prevent the Formation of 6389. Doebereiner's Self-Igniting a Crust in Tea-kettles. Keep an oystershell in your tea-kettle. By attracting the stony particles to itself, it will prevent the formation of a crust.

Lamp. Take an ordinary fruit jar, with a cork stopper or leaden cover; procure any old bottle that will go into the jar, at least two thirds as tall as the jar. Cut off the bot- つ tom of the bottle either with a file or by thoroughly pulverized, and 4 quarts soft wawrapping a piece of candle-wick soaked in alcohol around it, burning the wick, and dipping in water while hot. (See Nos. 2367, &c.) A hole is cut in the cork or lead cover, to admit the neck of the bottle and prevent it resting on the bottom of the jar. The bottle is closed with a cork fitted with a short glass ter. The above must be thoroughly shaken when first put together. It is required to, stand 24 hours to dissolve the chloride of lime; then strain through a cotton cloth; after which add a tea-spoonful of acetic acid (No. 8 commercial) to every ounce of the chloride of lime water. The eraser is used tube bent at right angles and drawn to a fine by reversing the pen-holder in the hand, dipopening. Some pieces of zinc are suspended ping the end of the pen-holder into the fluid, in the bottle by a wire or little basket of. lead. and applying it, without rubbing, to the The jar is then filled to about one-half with word, figure, or blot required to be erased. dilute sulphuric acid. The acid, coming in When the ink has disappeared, absorb the contact with the zinc, generates hydrogen fluid with a blotter, and the paper is immegas, which escapes from the glass tube. The diately ready to write upon again. Chloride mixture of air and gas being highly explo- of lime has before been used with acids for sive, the lamp should not be ignited until all the air has been expelled. After the air has escaped, a piece of spongy platinum may be placed a little distance from the point of the tube. The gas, impinging on the platinum, heats it sufficiently to ignite itself. The escape of gas may be cut off by slipping a rubber tube closed at one end over the glass tube, or a tube with a stop-cock may be used. As soon as the escape of gas is cut off, its pressure drives the acid out of the bottle into the jar, and no more gas generated. Pieces of spongy platinum mounted on wires suitable for this use may be obtained of dealers in chemical apparatus. The lamp may also be purchased complete from the same parties.