nium picrate and nitre, the proportions being 54 per cent.
picrate of ammonia and 46 per cent. potassic nitrate. It is stable, safe
to manufacture and handle, but expensive. It gives good results in the
Chassepot rifle, very little smoke, and its residue is small, and consists
of carbonate of potash. It is stated that 2.6 grms. used in a rifle gave
an effect equal to 5.5 grms. of ordinary gunpowder.

[Footnote A: The British Lydite and the Japanese Shimose are said to be
identical with Melinite.]

Turpin has patented various mixtures of picric acid, with gum-arabic,
oils, fats, collodion jelly, &c. When the last-named substance is diluted
in the proportion of from 3 to 5 per cent. in a mixture of ether and
alcohol, he states that the blocks of picric acid moulded with it will
explode in a closed chamber with a priming of from 1 to 3 grammes of
fulminate. He also casts picric acid into projectiles, the cast acid
having a density of about 1.6. In this state it resists the shock produced
by the firing of a cannon, when contained in a projectile, having an
initial velocity of 600 metres. It is made in the following way:--The acid
is fused in a vessel provided with a false bottom, heated to 130 deg. to 145 deg.
C. by a current of steam under pressure, or simply by the circulation
under the false bottom of a liquid, such as oil, chloride of zinc,
glycerine, &c., heated to the same temperature. The melted picric acid is
run into moulds of a form corresponding to that of the blocks required, or
it may be run into projectiles, which should be heated to a temperature of
about 100 deg. C., in order to prevent too rapid solidification.

When cresylic acid (or cresol, C_{6}H_{4}(CH_{3})OH.) is acted upon by
nitric acid it produces a series of nitro compounds very similar to those
formed by nitric acids on phenol, such as sodium di-nitro-cresylate, known
in the arts as victoria yellow. Naphthol, a phenol-like body obtained from
naphthalene, under the same conditions, produces sodium di-nitro-
naphthalic acid, C_{10}H_{6}(NO_{2})_{2}O. The explosive known as
"roburite" contains chloro-nitro-naphthalene, and romit, a Swedish
explosive, nitro-naphthalene.

~Tri-nitro-cresol~, C_{7}H_{4}(NO_{2})_{3}OH.--A body very similar to tri-
nitro-phenol, crystallises in yellow needles, slightly soluble in cold
water, rather more so in boiling water, alcohol, and ether. It melts at
about 100 deg. C. In France it is known as "Cresilite," and mixed