* It is now well ascertained, that carbonate of lime has only a slight action on soap, and cannot in the proportions in which it exists in potable waters decompose it, by giving rise to the formation of a clotty precipitate, as we observe with sulphate and nitrate of lime, and chloride of calcium -- and this is probably

owing to the excess of carbonic acid which prevents the re-action of the calcareous carbonate on the oleate and stearate of soda of the soap.

greater rapidity in pure running water. But if water be deprived of all its gases by ebullition, and excluded from contact with the air, the lead will not be acted upon If water, however, be exposed to the air, although all the gases have been expelled,

a white powder will soon form around the lead, till, in the course of a few days, there

is formed a large quantity of white, pearly scales, which partly float in the water,

but are chiefly deposited on the bottom of the vessel. In 12 ounces of distilled water, contained in a shallow glass basin, loosely covered to exclude the dust, twelve

brightly polished lead rods weighing 340 grains, will lose 2J grains in 8 days, and the lead will show evident marks of corrosion ; and this action will go on as long as

the water is exposed to the air. While these changes are going on, a small quantity of lead will be dissolved, as may be shown by carefully filtering the water acidulating