Armenian Cement.
| Mastic gum | 10 parts |
| Isinglass (fish glue) | 20 parts |
| Gum ammoniac | 5 parts |
| Alcohol absolute | 60 parts |
| Alcohol, 50 per cent | 35 parts |
| Water | 100 parts |
Dissolve the mastic in the absolute alcohol; dissolve, by the aid of gentle heat, on the water bath, the isinglass in the water, and add 10 parts of the dilute alcohol. Now dissolve the ammoniacum in the residue of the dilute alcohol. Add the first solution to the second, mix thoroughly by agitation and then add the solution of gum ammoniac and stir well in. Finally put on the water bath, and keeping at a moderate heat, evaporate the whole down to 175 parts.
Cement For Enameled Dials.
Watch-lid Cement.
Jewelers’ Glue Cement.
Casein Cements.—
| I.— | Borax | 5 parts |
|---|---|---|
| Water | 95 parts | |
| Casein, sufficient quantity. | ||
Dissolve the borax in water and incorporate enough casein to produce a mass of the proper consistency.
II.—The casein is made feebly alkaline by means of soda or potash lye and {21} then subjected for about 24 hours to a temperature of 140° F. Next follow the customary admixture, such as lime and water glass, and finally, to accomplish a quicker resinification, substances containing tannin are added. For tannic admixtures to the partially disintegrated casein, slight quantities—about 1 per cent—of gallic acid, cutch, or quercitannic acid are employed. The feebly alkaline casein cement containing tannic acid is used in the well-known manner for the gluing together of wood.