Young's Demonstrative Translation of Scientific Secrets / Or, A Collection of Above 500 Useful Receipts on a Variety of Subjects

by Daniel Young

137. CAST IRON CEMENT

Take of clean borings or turning of cast iron, 16 parts; of sal-ammoniac, 2 parts; and flour of sulphur, 1 part; mix them well together on a mortar, and keep them dry. When required for use, take 1 part of the mixture, and 20 parts of clean borings, mix thoroughly, and add a sufficient quantity of water. Note.—A little grindstone added improves the cement.

138. CASE HARDENING

This is the conversion of the surface of wrought iron into steel, for the purpose of adapting it to receive a polish, or to bear friction, &c. The best method in the world of effecting this is by heating the iron to cherry red in a close vessel, in contact with carbonacious material, and then plunging it into cold water. Bones, leather, hoofs, and horns of animals, are best for this purpose, after having been burnt or roasted, so that they can be pulverized. Soot is very frequently used; it answers, but not so well.