Bromide of Carbon.--Formed by mixing one part of periodide of carbon with two of bromine. Two compounds are formed, the _bromide of carbon_, and the _sub-bromide of iodine_; the latter is removed by a solution of caustic potassa. It is liquid at common temperatures, but crystallizes at 32° Fahr.; sweet to the taste, and of a penetrating ethereal odor; distinguished from the protiodide by the vapor which it emits on being heated. The _periodide of carbon_ is made by mixing an alcoholic solution of pure potash and of iodine. It forms crystals of a pearly lustre, sweet to the taste, and of a saffron odor. The _protiodide_ is formed by distilling a mixture of the preceding compound with corrosive sublimate. Sweet in taste, and of a penetrating ethereal odor. Bromide of Magnesium.--Dissolve magnesia in hydrobromic acid. It will crystallize in small acicular crystals, of a sharp taste, very deliquescent and soluble. Bromide of Sulphur.--Pour bromine on sublimed sulphur. There is formed an oily liquid of a reddish tint. Bromide of Phosphorus, is formed by bringing phosphorus and bromine into contact in a jar filled with carbonic acid gas. Vaporizes by heat, and is decomposed by water. Bromide of Silicon, is prepared by burning silicon in the vapor of bromine. A very dense, colorless liquid, emitting dense fumes. We have used this article as an accelerator, and it produces a beautiful but singular picture. It works quick, but possesses no particular advantage. Bromide of Zinc.--Prepared by digesting a solution of bromine with zinc filings. The iodide is formed in a similar manner. No interest. Hydrobromic Acid.--Mix the vapor of bromine with about an equal bulk of hydrogen gas, and introduce a coil of red-hot platinum wire. Red-hot iron answers equally well. The combination takes place slowly without explosion. Or, it may be formed by placing a small piece of phosphorus in a glass tube filled with water, and dropping it upon a little bromine. The hydrobromic acid passes over in the form of a gas, and may be passed through water, which will absorb it. _Hydriodic Acid_ is formed in the same way, using iodine in place of the bromine. Hydrobromic acid is decomposed instantly by chlorine and nitric acid. The French and German bromine is generally considered the best; but the American manufacture is by no means to be rejected, as it is frequently very excellent. Bromine is sometimes adulterated with naphtha. * * * * * NITRATE OF SILVER. DECOMPOSED BY THE CURRENT OF A GALVANIC BATTERY.