l residue only of carbonate of potash.

The next in importance is _Designolle's Powder_, made at Bouchon,
consisting of picrate of potash, saltpetre, and charcoal. It was made in
three varieties, viz., for rifles, big guns, and torpedoes and shells.
These powders are made much in the same way as gunpowder. The advantages
claimed for them over gunpowder are, greater strength, comparative absence
of smoke, and freedom from injurious action on the bores of guns.

_Emmensite_ is the invention of Dr Stephen Emmens, of the United States.
The Emmens "crystals" are produced by treating picric acid with fuming
nitric acid of specific gravity of 1.52. The acid dissolves with the
evolution of red fumes. The liquid, when cooled, deposits crystals, stated
to be different to picric acid, and lustrous flakes. These flakes, when
heated in water, separate into two new bodies. One of these enters into
solution and forms crystals unlike the first, while the other body remains
undissolved. The acid crystals are used mixed with a nitrate.

Emmensite has been subjected to experiment by the direction of the U.S.
Secretary for War, and found satisfactory. A sample of Emmensite, in the
form of a coarse powder, was first tried in a pistol, and proved superior
in propelling power to ordinary gunpowder. When tested against explosive
gelatine, it did very good work in shattering iron plates. It is claimed
for this explosive that it enjoys the distinction of being the only high
explosive which may be used both for firearms and blasting. This view is
supported by the trials made by the American War Office authorities, and
shows Emmensite to be a useful explosive both for blasting and as a
smokeless powder. Its explosive power, as tested, is 283 tons per square
inch, and its specific gravity is 1.8.

Abel proposed to use picric acid for filling shells. His _Picric Powder_
consisted of 3 parts of saltpetre, and 2 of picrate of ammonia.
_Victorite_ consists of chlorate of potash, picric acid, and olive oil,
and with occasionally some charcoal. It has the form of a coarse yellowish
grey powder, and leaves an oily stain on paper, and it is very sensitive
to friction and percussion. The composition is as follows:--KClO_{3} = 80
parts; picric acid, 110 parts; saltpetre, 10 parts; charcoal, 5 parts. It
is not manufactured in England. _Tschiner's Powder_ is very similar to
Victorite in composition, but contains resin. A list of the chief picric
powders will