Tut. They are all so in some degree, producing violent sickness and pain in the bowels. They are all, too, extremely nauseous to the taste, and the metal itself when heated, tastes and smells very disagreeably.
Har. Why is it used, then, so much in cooking, brewing, and the like?
Tut. Because it is a very convenient metal for making vessels, especially large ones, as it is easily worked, and is sufficiently strong, though hammered thin, and bears the fire well. And if vessels of it are kept quite clean, and the liquor not suffered to stand long in them when cold there is no danger in their use. But copper vessels for cooking are generally lined on the inside with tin.
Geo. What else is copper used for?
Tut. A variety of things. Sheets of copper are sometimes used to cover buildings; and of late a great quantity is consumed in sheathing ships, that is, in covering all the part under water; the purpose of which is, to protect the timber from the worms, and also to make the ship sail faster, by means of the smoothness and therefore less obstruction which the copper offers to the water, as the ship is forced through it by the action of the wind on the sails.
Har. Money is made of copper, too.
Tut. It is; for it takes an impression in coining very well, and its value is a proper proportion below silver, for a price for the cheapest commodities. In some poor countries they have little other than copper coin. Another great use of copper is as an ingredient in mixed metals, such as bell-metal, cannon-metal, and particularly brass.
Har. But brass is yellow.
Tut. True; it is converted to that colour by means of another metallic substance, named zinc or spelter, the natural colour of which is white. A kind of brown stone called calamine is an ore of zinc. By filling a pot with layers of powdered calamine and charcoal placed alternately with copper, and applying a pretty strong heat, the zinc is driven in vapour out of the calamine, and penetrates the copper, changing it into brass.
Geo. What is the use of turning copper into brass?