Almond paste.—(a) Ground almond cake, from which the oil has been expressed, is mixed up with an equal weight of whiting, and made into a stiff paste with water. It soon becomes very hard and tough. It is much employed for stills, retorts, &c., where the heat does not exceed about 160° (320° F.); it is capable of resistinz the fumes of volatile oils, spirits, weak acids, &c., for some tirne. (b) Ground almond cake as before (or linseed cake) is added to starch paste and gum water.
Aquariums, for.—(a) Plaster of Paris, 1 gill ; litharge, 1 gill ; flne white sand, 1 gill; fmely powdered rosin, * gill; well mixed, bottled and corked till required ; for use, it is mingled with boiled oil and (biers till it is as thick ns putty. It dries quickly. (b) Boiled linseed oil, litharge, and a mixture of red and white lead (the latter in excess), spread on a flannel, snd placed on the joint. (c) Glue, 8 oz.; dissolved in Venice turpentine, 1 oz.; boiled together with constant agita tion till the mixture is complete ; the joints to be luted should be compressed for forty-eight hours, if necessary. (d) Gold-size, gill ; red-lead, 2 gills ; litharge, gill ; silver sand, sufficient to make the mass into a thick paste ; sets in about two days.
Bottle-corks, for.—(a) A paste composed of commercial silicate of soda and pulverized kaolin, with or without chalk, is applied to the corks and left to dry. (b) Rosin,1 lb. ; tallow or suet, lb.; melted together ; sufficient colouring matter is stirred in. (c) Rosin, 5 lb. ; beeswax, 1 lb.; colour ing, as last. (d) To 1 lb. of the last, is added finely powdered dry whiting, 3 oz. ; powdered burnt ochre, 4 oz. (or red bole, sufficient to produce desired red tint). (e) To 1 Ill. of b, or c, add ivory black, sufficient to produce black colour. (f ) Black pitch, 6 lb. ; ivory-black, 1 lb.; whiting, 1 lb. ; melted together ; used in the same way as common sealing-wax on corks and bungs.
Brimstone.—Melted brimstone, either alone or mixed with roein and brickdust. It is cheap and useful.
Cap.—(a) Rosin, 5 lb. ; beeswax, 1 lb. ; dried Venetian red, 1 lb.; melted together. (b) Red lead and white-lead, equal weights ; preferable to white-lead alone, and may be depended on fur any temperature up to 100° (212° F.). These lutes are used for chemical and electrical purposes, e. g. connections of glass tubes, necks of balloons, &c., in metal mountings.
Chemical.—(a) Yellow wax, 4 parts ; common turpentine, 2 parts; well-dried Venetian red, 1 part; melted together. Used as a temporary lute for the ends and joints of tubes which are not exposed to much heat, as is alkalimetry, &c. (b) Slaked lime is beaten up with white of egg; strips of linen are soaked in the mixture, and applied immediately, as it dries very rapidly. (c) Pulverized chalk, part ; rye flour, 1 part ; white of egg, a sufficiency; the whole is formed into an almost liquid mass, which is brushed over strips of linen, and the latter are applied to the joint ; an additional strip of linen is laid over them, and pressed with a hot iron, which dries the com pound.
Copperemiths'.—Bullock's blood thickened with finely powdered quicklime. Must be applied promptly, as it sets rapidly. Used under the edges, and rivets of copper boilers, &c.; it is cheap and durable, and suited for many other purposes.
Crucibles, for.—A mixture of powdered clay and brickdust, made up with water, or a solution of borax. Used to join crucibles which are exposed to a strong heat. When mixed up with borax solution, the lute becomes a compact vitreous mass in the fire.
Dilal's.—A mixture of boiled linseed oil, litharge, and powdered china-clay. The whole is made into a paste, and applied with a trowel. The surfaces of the joint must previously be thoroughly cleaned and dried, or the lute will not answer ; it is useful in damp places.
Engineers'.—(a) Ground white-lead is mixed with as much red-lead as will give the mass the consistence of putty. (b) White-lead and red-lead in equal weights, and boiled linseed oil, sufficient te produce the proper consistence. These compounds are applied hy smearing them on a was13er of hemp, yarn, &c., placed between metallic joints which are to be screwed up. They also answer well for luting the joints between stones, e. g. in cisterns, &c., and dry as hard as stone.
Fat. — (a) Clay is dried, powdered, sifted, placed in an iron mortar, and incorporated with drying oil, added gradually, the whole being well beaten up till the mass assumes the consistence of a fine paste. lt should be preserved under a coating of oil, to prevent it drying up. It resists the action of corrosive gases, but inconveniently softens by exposure to heat. (b) Plaeter of Paris mixed with water, milk, or weak glue. Stands a dull red heat.