‹‹‹ Vitr. 1.4.2 | Table of Contents | Vitr. 1.4.4 ›››
3For heat, which acts as an alterative, by drying up the natural moisture of any body, destroys and rots those substances on which it acts. Iron, for instance, naturally of a hard texture, becomes so soft when heated in a forge as to be easily wrought into any form; but if, when heated, it is suddenly immersed in cold water, it immediately regains its original quality.
3For heat is a universal solvent, melting out of things their power of resistance, and sucking away and removing their natural strength with its fiery exhalations so that they grow soft, and hence weak, under its glow. We see this in the case of iron which, however hard it may naturally be, yet when heated thoroughly in a furnace fire can be easily worked into any kind of shape, and still, if cooled while it is soft and white hot, it hardens again with a mere dip into cold water and takes on its former quality.