But the Lord's word endures forever." This is the word of good news which was preached to you.
Sulphur, in the state of a sulphuret, dissolves it; tin and lead greatly impair its tenacity; and zinc hardens and renders it very brittle. Copper heightens its colour, and renders it harder, without greatly impairing its ductility. It readily unites with iron, which it hardens in a remarkable manner.