- 168 " 167 " 76 " At Carshamm, - - - - - 66 " The average quantity of saline matter in sea-water is 3| per cent., and its specific gravity about 1.0274. The composition of sea-water differs also in different localities. Iodine has been found in the Mediterranean sea. Action of Water on Lead. When lead is exposed to atmospheric air, the oxygen of the air combining with it, forms an oxide, while, at the same time the carbonic acid of the air, unites with it forming a thin white crust, which is the carbonate of

lead. This formation is accelerated by moisture, and by the presence of an unusual quantity of carbonic acid in the atmosphere. The same process goes on with still

* 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,