Page:The chemical history of a candle.djvu/228

226 grain of water as there is in a very powerful flash of lightning.

($15$) Page 101. A solution of acetate of lead submitted to the action of the voltaic current, yields lead at the negative pole, and brown peroxide of lead at the positive pole. A solution of nitrate of silver, under the same circumstances, yields silver at the negative pole, and peroxide of silver at the positive pole.

($16$) Page 129. The gas which is thus employed as a test for the presence of oxygen, is the binoxide of nitrogen, or nitrous oxide. It is a colourless gas, which, when brought in contact with oxygen, unites with it, forming hyponitric acid, the red gas referred to.

($17$) Page 152. Marble is a compound of carbonic acid and lime. The muriatic acid being the stronger of the two, takes the place of the carbonic acid, which escapes as a gas, the residue forming muriate of lime or chloride of calcium.

($18$) Page 186. Lead pyrophorus is made by heating dry tartrate of lead in a glass tube (closed at one end, and drawn out to a fine point at the other) until no more vapours are evolved. The open end of the tube is then to be sealed before the blowpipe. When the tube is broken and the contents shaken out into the air, they burn with a red flash.

($19$) Page 216. Water-gas is formed by passing vapour of water over red-hot charcoal or coke. It is a mixture of hydrogen and carbonic oxide, each of which is an inflammable gas

BELL AND BAIN, LIMITED, PRINTERS, GLASGOW.