Cooley's cyclopaedia of practical receipts and collateral information in the arts, manufactures, professions, and trades including medicine, pharmacy, hygiene, and domestic economy : designed as a comprehensive supplement to the Pharmacopoeia and general book of reference for the manufacturer, tradesman, amateur, and heads of families . ution treatedwith a few drops of sulphurous acid, and sub-sequently with sulphuretted hydrogen, gives acanary-yellow precipitate of trisulphide of ar-senic, which readily redissolves, forming acolourless solution with ammonia.—The ar-senical spot, when heated,
Cooley's cyclopaedia of practical receipts and collateral information in the arts, manufactures, professions, and trades including medicine, pharmacy, hygiene, and domestic economy : designed as a comprehensive supplement to the Pharmacopoeia and general book of reference for the manufacturer, tradesman, amateur, and heads of families . ution treatedwith a few drops of sulphurous acid, and sub-sequently with sulphuretted hydrogen, gives acanary-yellow precipitate of trisulphide of ar-senic, which readily redissolves, forming acolourless solution with ammonia.—The ar-senical spot, when heated, is turned brightyellow by sulphuretted hydrogen, and is thenreadily dissolved, as before, by ammonia, andby its bicarbonate ; whereas one of antimonyis turned of a deep orange-red, or reddish-brown, by sulphuretted hydrogen, is notreadily dissolved by ammonia, and is scarcelyor not at all affected by bicarbonate of ammo-nia.—It is freely soluble in and removed byhypochlorite of soda; a reagent which doesnot affect antimonial spots. Heated by afiame of pure hydrogen an arsenical stainrapidly disappears. A mixed stain of anti-mony and arsenic does not disappear by theaction of the last two reagents, and is shownto contain arsenic by the two first tests hydrochloric acid is present zinc stains 102 ARSENIOUS ANHYDRIDE. are sometimes formed, but they do not re-semble those from arsenic. The flame whichproduces it is very pale blue or bluish-white;whereas antimoniuretted hydrogen burns witha pale green or greenish-yellow flame, and awhite smoke, both of which are Marshs test is admirable for its sim-plicity, delicacy, and trustworthiness, as well asfor the ease of its application. It is adaptedto all liquids, whether colourless or coloured,which are not so glutinous as to inconvenientlyfroth during the extri-cation of the hydrogen.!Various modifications ofthe original apparatushave been proposed toobviate this difficulty;among which the onechiefly d
Size: 1053px × 2374px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, books, booksubjectrecipes, booksubjecttechnology
