from potash by means of a powerful voltaic battery. Its great affinity for
oxygen causes it to decompose water with evolution of hydrogen, which
takes fire with the heat produced.]
[Footnote 14: Page 98. Professor Faraday has calculated that there is as
much electricity required to decompose one grain of water as there is in a
very powerful flash of lightning.]
[Footnote 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.]
[Footnote 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.]
[Footnote 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.]
[Footnote 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.]
[Footnote 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.]
Poster s note: combustion that makes! was corrected from a misprint
combusion that makes! in the original.
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