Scheibler’s cement for chemical apparatus:—
| Gutta-percha | 2 |
| Wax | 1 |
| Shellac | 3 |
Sorel’s Cement.—This consists of oxide of zinc combined with its chloride. The chloride of zinc is in a heavy, syrupy form, which, combined with the white oxide, sets very hard. It is chiefly used for filling teeth, but is also applicable to making medallions and other objects of art. For this latter purpose it is mixed with powdered chalk, pulverised glass, &c. The process of preparing and combining the ingredients of this cement is, however, so tedious that it is most unlikely that the ordinary repairer will care to attempt it; the more so as there are many preparations far superior to it.
Glue for tapestry, &c.:—
| Flour-paste | 100 |
| Alum water | 3 |
| Dextrine-paste | 5 |
This may also be applied in many ways.
To lute stills, &c.:—
| Glue in powder | 20 |
| Flour | 10 |
| Bran | 5 |
To be well mixed with water.
As alum cannot be affected by petroleum, it is used to fasten rings to petroleum-lamp holders. These are lined with alum which has been melted by heat. Alum melted forms a strong cement for glass and metal.