[17] Page 106. _Chlorate of Potash and Sulphuret of Antimony._--Great
care must be taken in mixing these substances, as the mixture is
dangerously explosive. They must be powdered separately, and mixed
together with a feather on a sheet of paper, or by passing them several
times through a small sieve.
[18] Page 107. The mixture of chlorate of potash and sugar does not
require the same precautions. They may be rubbed together in a pestle
and mortar without fear. One part of chlorate of potash and three parts
of sugar will answer. The mixture need only be touched with a glass rod
dipped in oil of vitriol.
[19] Page 107. _Two Salts Dissolved in Water._--Sulphate of soda and
chloride of calcium. The solutions must be saturated for the experiment
to succeed well.
[20] Page 111. _Lead Pyrophorous._--This is a tartrate of lead which
has been heated in a glass tube to dull redness as long as vapours are
emitted. As soon as they cease to be evolved, the end of the tube is
sealed, and it is allowed to cool.
[21] Page 115. _Gun-Cotton_ is made by immersing cotton-wool in
a mixture of sulphuric acid and the strongest nitric acid, or of
sulphuric acid and nitrate of potash.
[22] Page 115. _Paper Prepared like Gun-Cotton._--It should be bibulous
paper, and must be soaked for ten minutes in a mixture of ten parts by
measure of oil of vitriol with five parts of strong fuming nitric acid.
The paper must afterwards be thoroughly washed with warm distilled
water, and then carefully dried at a gentle heat. The paper is then
saturated with chlorate of strontia, or chlorate of baryta, or nitrate
of copper, by immersion in a warm solution of these salts. (See
_Chemical News_, Vol. I., page 36.)