Tut. That is oxide of lead exposed for a considerable time to a strong flame. Lead may even be changed into glass by a moderate heat; and there is a good deal of it in our finest glass.
Geo. What is white lead?
Tut. It is lead corroded by the steam of vinegar. Lead in various forms is much used by painters. Its oxides dissolve in oil, and are employed for the purpose of thickening paint and making it dry. All lead paints, however, are unwholesome as long as they continue to smell, and the fumes of lead, when melted, are likewise pernicious. This is the cause why painters and plumbers are so subject to various diseases, particularly violent colics and palsies. The white-lead manufacture is so hurtful to the health, that the workmen, in a very short time, are apt to lose the use of their limbs, and be otherwise severely indisposed.
Geo. I wonder, then, that anybody will work in it.
Tut. Ignorance and high wages are sufficient to induce them. But it is to be lamented that in a great many manufactures the health and lives of individuals are sacrificed to the convenience and profit of the community. Lead, too, when dissolved, as it may be in all sour liquors, is a slow poison, and the more dangerous, as it gives no disagreeable taste. A salt of lead made with vinegar, is so sweet, as to be called the sugar of lead. It has been too common to put this or some other preparation of lead into sour wines, in order to cure them; and much mischief has been done by this practice.
Geo. If lead is poisonous, is it not wrong to make water-pipes and cisterns of it?
Tut. This has been objected to; but it does not appear that water can dissolve any of the lead. Nor does it readily rust in the air, and hence it is much used to cover buildings with, as well as to line spouts and water-courses. For these purposes the lead is cast into sheets, which are easily cut and hammered into any shape.
Har. Bullets and shot, too, are made of lead.
Tut. They are; and in this way they are ten times more destructive than as a poison.
Geo. I think lead seems to be more used than any metal except iron.