Red Cement which is employed by instrument makers for cementing glass to metals, and which is very cheap, and exceedingly useful for a variety of purposes, is made by melting five parts of black rosin, one part of yellow wax, and then stirring in gradually one part of red ochre or Venetian red, in fine powder, and previously
well dried
. This cement requires to be melted before use, and it adheres better if the objects to which it is applied are warmed.
2502. A Soft Cement for Corks
A soft cement, of a somewhat similar character to that just described, is useful for covering the corks of preserved fruit, and other bottles. It is made by melting yellow wax with an equal quantity of rosin, or of common turpentine (not oil of turpentine, but the resin), using the latter for a very soft cement, and stirring in, as before, some dried Venetian red.
2503. Mastic Cement
This is employed for making a superior coating to inside walls, but must not be confounded with the
resin mastic