Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Acid-Proof Cement
A cement that resists acid is made by melting one part India rubber with two parts linseed oil; add sufficient white bolus for consistency. Neither muriatic nor nitric acid attack it; it softens a little in heat, and its surface does not dry easily; which is produced by adding one-fifth part litharge.