Lyddite,[A] the picric acid explosive used in the British service, is supposed to be identical with the original melinite, but its composition has not been made public.

[Footnote A:  Schimose, the Japanese powder, is stated to be identical with Lyddite and Melinite (Chem.  Centr., 1906, 1, 1196).]

Picrates are more often used than picric acid itself in powders.  One of the best known is Brugere’s Powder, which is a mixture of 54 parts of picrate of ammonia and 45 parts of saltpetre.  It is stable and safe to manufacture.  It has been used in the Chassepot rifle with good results, gives little smoke, and a small 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 be found in the late Colonel J.P.  Cundill, R.A.’s “Dictionary of Explosives.”