also gave satisfactory results with nitro-glycerine.
The dry substance may now be wrapped in filter paper, the whole weighed,
and the nitro-glycerine extracted in the Soxhlet apparatus with ether. The
ether should be distilled over at least twenty-four times.

I have found, however, that much quicker, and quite as accurate, results
may be obtained by leaving the dynamite in contact with ether in a small
Erlenmeyer flask for twenty-four hours--leaving it overnight is better--
and decanting, and again allowing the substance to remain in contact with
a little fresh ether for an hour, and finally filtering through a weighed
filter, drying at 100 deg. C., and weighing. This gives the weight of the
kieselguhr. The nitro-glycerine must be obtained by difference, as it is
quite useless to evaporate down the ethereal solution to obtain it, as it
is itself volatile to a very considerable extent at the temperature of
evaporation of the ether, and the result, therefore, will always be much
too low. The dry guhr can, of course, be examined, either qualitatively or
quantitatively, for other mineral salts, such as carbonate of soda, &c. An
actual analysis of dynamite No. 1 made by the author at Hayle gave--
Moisture, 0.92 per cent.; kieselguhr, 26.15 per cent.; and nitro-
glycerine, 72.93 per cent., the last being obtained by difference.

~Nitro-Glycerine.~--It is sometimes desired to test an explosive substance
for nitro-glycerine. If an oily liquid is oozing from the substance, soak
a drop of it in filter paper. If it is nitro-glycerine it will make a
greasy spot. If the paper is now placed upon an iron anvil, and struck
with an iron hammer, it will explode with a sharp report, if lighted it
burns with a yellowish to greenish flame, emitting a crackling sound, and
placed upon an iron plate and heated from beneath, it explodes sharply.

If a few drops of nitro-glycerine are placed in a test tube, and shaken up
with methyl-alcohol (previously tested with distilled water, to see that
it produces no turbidity), and filtered, on the addition of distilled
water, the solution will become milky, and the nitro-glycerine will
separate out, and finally collect at the bottom of the tube.

If to a solution of a trace of nitro-glycerine in methyl-alcohol, a few
drops of a solution, composed of 1 volume of aniline, and 40 volumes
sulphuric acid (1.84) be added, a deep purple colour will be produced.
This colour changes to green upon the addition