the weight and description of the contents. The boxes should then be
removed to the magazines. It is well to take a certain number of
cartridges from the packing house at different times during the day, say
three or four samples, and to test them by the heat test. A sample cut
from a cartridge, about 1 inch long, should be placed under a glass shade,
together with water (a large desiccator, in fact), and left for some days.
A good dynamite should not, under these conditions, show any signs of
exudation, even after weeks.[A]

[Footnote A: For analysis of dynamite, see chapter on "Analysis," and
author's article in _Chem. News_, 23rd September 1892.]

~Properties of Kieselguhr Dynamite.~--One cubic foot of dynamite weighs 76
lbs. 4 oz. The specific gravity of 75 per cent. dynamite is, however,
1.50. It is a red or grey colour, and rather greasy to the touch. It is
much less sensitive to shock than nitro-glycerine, but explodes
occasionally with the shock of a rifle bullet, or when struck. The
addition of a few per cent. of camphor will considerably diminish its
explosive qualities to such an extent that it can be made non-explosive
except to a very strong fulminate detonator. The direct contact of water
disintegrates dynamite, separating the nitro-glycerine, hence great
caution is necessary in using it in wet places. It freezes at about 40°
Fahr. (4° C.), and remains frozen at temperatures considerably exceeding
that point. When frozen, it is comparatively useless as an explosive
agent, and must be thawed with care. This is best done by placing the
cartridges in a warming pan, which consists of a tin can, with double
sides and bottom, into which hot water (130° Fahr.) can be poured. The
dynamite will require to be left in for some considerable time before it
becomes soft. On no account must it be placed on a hot stove or near a
fire, as many serious accidents have occurred in this way.