The picrate so formed is then decomposed by ammonia.
Silver picrate and methyl iodide yield the methyl ester, which gives with ammonia picramide.
The more important picric powders are melinite, believed to be a mixture of fused picric acid and gun-cotton; lyddite, the British service explosive, and shimose, the Japanese powder, both supposed to be identical with the original melinite; Brugere's powder, a mixture of 54 parts of ammonium picrate and 45 parts of saltpetre; Designolle's powder, composed of potassium picrate, saltpetre and charcoal; and emmensite, invented by Stephen Emmens, of the United States.
The fluorene is separated from this by placing it in a freezing mixture, and is then redistilled or crystallized from glacial acetic acid, or purified by means of its picrate.