27. Crazed periode of iron. Dark-brown, brittle while bur becoming plastic when heated, easily soluble in water. Aleveling to M. H. Rose, the solution of this salt is not pre es. Malmed penode of iron. A brown, gum-like mass, not altered by exposure to the air, easily soluble in water, and This sit is not precipitated by the alkalies.* 29. Fyrrawn shed pen zide of iron. A lemon-yellow powder. 30. Seconutted per szude of iron. Succinate of potash or of ates peroxide of iron from its neutral solutions, riskered dicks, which become darker coloured This salt is not soluble in cold water; but when water, it is decomposed into bisuccinate, which disdisuccinate, which remains in the state of an inso From the analysis of Bucholz, this salt, when in the open air, would seem to be a compound of 1 arem succinic aci 6.25 atom peroxide of iron Ijarom water 5-00 1-6878 12-9375t $1. Bison wired pemande of aron. Obtained by boiling the sult in water. The solution is not precipitated by When concentrated by evaporation, it deposites mad peromide of iron. The powder which when succinated peroxide of iron is boiled It domains very little acid: but has not yet been It was M. Rose, serier, that first pointed out the method of perox, le of iron from manganese, by means of an rate. Foemia de fum. Benzoate of ammonia comates a neutral persalt of iron. The precipitate When Leated, it melts into a reddish-yellow, acid is destroyed, and protoxide of iron remains. so't is digested in aqueous potash or ammonia, the parna y fecomposed, and a reddish-coloured solution is De sit is also decomposed into super and sub benzoates, by boiling it in a great deal of water. When dried Sect. XVIL at 212°, it is anhydrous, and composed of 34. Bibenzoated peroxide of iron. When the preceding salt is digested with benzoic acid and water, a solution is obtained, which, when sufficiently concentrated, deposites bibenzoate in yellow crystals, which effloresce in the air, and are partially soluble in water and alcohol.* 35. Subbenzoated peroxide of iron. It is obtained when the neutral salt is boiled in water, or treated with an alkali. 36. Gallated peroxide of iron, Gallic acid throws down peroxide of iron from its solution in acid, in the state of a very deep blue powder, the constitution of which has not yet been determined. 37. Meconated peroxide of iron, Meconic acid and its salts gives a beautiful red colour to the peroxidized salts of iron, without occasioning any precipitate. Exposure to the light of the sun, or a mixture of protochloride of tin, completely destroys this red colour. 38. Boletated peroxide of iron. Boletic acid, or its alkaline salts, precipitate sulphated peroxide of iron, in the state of an aurora red magma. 39. Camphorated peroxide of iron. When camphorate of potash is dropt into a persalt of iron, a bulky, light-brown precipitate falls, which is insoluble in water.† 40. Suberated peroxide of iron. It may be obtained by double decomposition, in the same way as the preceding salt, which it closely resembles in appearance and properties.+ 41. Pinated peroxide of iron. This salt is obtained when alcoholic solutions of pinic acid and perchloride of iron are mixed together. The tarry precipitate is to be washed with alcohol. A brown, opaque, brittle mass, soluble with difficulty in alcohol, but easily soluble in ether and oil of turpentine.§ 42. Silvated peroxide of iron. It may be prepared in the same way as the preceding salt. It is but little soluble in alcohol, but very soluble in ether.|| * Trommsdorf. + Brandes, Schweigger's Jour. xxxviii. 299, Brandes, ibid. xxxiii. 102. § Unverdorben, Poggendorf's Annalen, xi. 235. Ibid. p. 401. prate. 3. M. When wirl car kafiron. A chamois yellow powder.* IF PROTOXIDE OF MANGANESE. In fions of protoxide of manganese with water The solutions are colourless, and i siline taste: by no means so disagreeable tite salts. When the solutions are suffil. many of the salts of manganese crystalstals have a feshered colour, which, together gives them a beautiful appearance. f the salts of manganese are treated deposite a white precipitate, which when exposed to the air. ush occasions a white precipitate when tash eccusions a yellowish precipiren is gives the solution a white ecipitate, unless the acid be weak. of nut-galls, occasion no preci nt precipitated from its solution in the any of the other metals. allese are not precipitated by succinate a white precipitate, which gradually access. If we add some sal ammoniac, eg able of throwing down the protoxide tin of sal ammoniac immediately dis rown down by ammonia. But on exposed to the air. the precipitate again Sit of manganese is heated before the blowite of soda, it fuses into a green glass, which Mell-green when cold. With borax in the oxidizan amethyst-coloured glass; but in the the eclour disappears. This salt is easily formed, by the carb rate of manganese in sulphuric acid to crystallizing the solution. The crystals are le prisms, the inclination of the faces being It bears a considerable resemblance to Úེ་་ very gre, Ann. de Chim et de Phys. xiii. lol. the crystalline form of axinite. It is transparent, and has a Sect. XVIII. slight shade of red, which gives it a beautiful appearance. When exposed to the air, it undergoes very little alteration, or becomes only slightly efflorescent. The taste is bitter, and similar to that of glauber salt, but stronger; and, like glauber salt, it may be administered as a cathartic, in doses of from half an ounce to an ounce. Its specific gravity is 2.877. 100 parts of water at the temperature of 40° dissolve 31 parts of this salt previously dried in the temperature of 150°. It is insoluble in alcohol.* When heated, its water is driven off, and it falls down in the state of a white powder. I found its constituents as follows: But Mitcherlich (who at first obtained the same quantity of water that I did) has more lately announced that the salt con tains only 4 atoms of water. If this statement be correct the When the solution of sulphate of manganese is concentrated rather too far, a white crust is deposited on the bottom of the vessel. This crust is rather difficultly soluble in water, and is a compound of 2. Subsesquisulphate of manganese. Pfaff informs us that by digesting native deutoxide of manganese in sulphuric acid and evaporating the solution, he obtains two different kinds of crystals, the first kind constitute the crystals of the last species, the other crystals he describes as perfectly white, and composed of doubly oblique four-sided prisms, but not nearly so much so as the preceding salt. He informs us that the constituents of this salt are: * John, Annals of Philosophy, ii. 183. It is doubtful whether it be a disulphate or subsesquisulphate. Were we to adopt the latter opinion, the composition of the salt would probably be 1 atom sulphuric acid 1 atom manganese 3. Sulphite of manganese. It may be obtained by digesting carbonate of manganese in liquid sulphurous acid. It is a white granular tasteless powder, not altered by exposure to the air, insoluble in water and alcohol, and decomposed by exposure to a red heat. Its constituents, according to Dr. John, to whom we owe the preceding facts, are Protoxide of manganese Acid and water This approaches 1 atom sulphurous acid 1 atom protoxide of manganese 21 atoms water 40.2 59.8 100.0 4 4.5 2.8125 11.3125 4. Hyposulphite of manganese. This salt remains in solution when hyposulphite of lime is precipitated by sulphate of manganese.+ 5. Hyposulphate of manganese. This salt is very soluble in water, and even deliquescent.‡ 6. Nitrate of manganese. Nitric acid dissolves manganese with effervescence, occasioned by the emission of nitric gas. • Schweigger's Jahrbuch. xxiii. 121. + Herschell, Edin. Phil. Jour. i. 24. Gay-Lussac; Annals of Philosophy, xiv. 355. |