1. Keller's. Soak 2 drs. of cut isinglass in 2 oz. of water for 24 hours; boil to 1 oz., add 1 oz. methylated spirit of wine, and strain through linen. Mix this, while hot, with a solution of 1 dr. of mastic in 1 oz. of methylated spirit, and triturate with 1/2 dr. powdered gum ammoniac, till perfectly homogeneous.

2. Dr. Ure's Diamond Cement. Isinglass 1 oz., distilled water 6 oz., boil to 3 oz., and add 1 1/2 oz. of methylated spirit. Boil for a minute or two, strain, and add while hot, first 1/2 oz. of a milky emulsion of ammoniac, and then 5 drs. of tincture of mastic. [There are various kinds of this cement sold, and some of the improvements introduced by peculiar makers have not been made public]

Cement used in the East for uniting jewels, glass, and metals. Dissolve 5 or 6 pieces of gum mastic, each about the size of a large pea, in just as much methylated spirit as will render it liquid. Soften some isinglass by steeping it in water; having dried it, dissolve as much of it in good brandy as will make a two-ounce phial of strong glue, to which must be added two small bits of gum ammoniacum, rubbing until they are dissolved. Mix the two solutions; keep in a close phial; and when it is to be used, set the phial in boiling water. - Mr. Eton.

Liquid Cement, for glass, porcelain, wood, etc. Macerate for several hours sis parts of glue in small pieces, in 16 parts of water, add 1 part hydrochloric acid and 1 1/2 part of sulphate of zinc, and expose the mixture for several hours to a temperature of 150° F.