We give the folk wing interesting combination and experiments with bromine, as found in Hill's Treatise:—

"Discovered in 1826, by M. Balard, a young chemist of Montpellier, France. He named it Muride, because obtained from the sea; but it acquired its present name from a Greek word, signifying rank, or dead odor." It exists in nature in very small quantities. It is found in the waters of every sea which has been tested for it: it is also found in many mineral and salt springs. We have not been able to determine to whom belongs the honor of discovering its use as an accelerator in Daguerreotype. Having corresponded with Prof. Morse, (who was certainly one of the first who took portraits by the Daguerreian process,) Dr. Draper, and others, to whom this honor has been awarded, they refuse to claim it. Prof. Silliman, who is supposed to know everything relating to science, writes to me that he does not know this. I am quite inclined to place the wreath on the brow of the inventor of the Magnetic Telegraph.

Process.—When common salt is prepared from sea-water by evaporation and crystallization, a liquid remains which goes under the name of bittern. This liquid on passing chlorine through it, is tinged with a deep yellow color. The liquid is now distilled, and the vapor passed over a substance, (muriate of lime), which has a powerful attraction for water. A small quantity of bromine is thus obtained.—Another method is to agitate the chlorinated bittern with a portion of sulphuric ether. The ether dissolves the bromine, from which it receives a beautiful red tint, and on standing, rises to the surface. Agitate this solution with caustic potash, and the bromide of potassium and bromate of potassa will be formed. Evaporate the liquor and the bromide of potassium will be left from which bromine may be distilled.

Properties.—At common temperatures, it rapidly volatilizes, giving red vapors of a most disagreeable smell. Its color, when held between the eye and the light is a deep hyacinth red. Like oxygen, chlorine, and iodine, it is a non-conductor of electricity, and a negative electric. It boils at 116·5°, and congeals at 40 Fahr. into a brittle solid. It is a powerful poison; even its vapor would no doubt prove fatal, if inhaled in large quantities. A single drop placed in the beak of a bird destroys it instantly. Operators cannot be too cautious in using it. A very small drop spattered in the eye would destroy the sight. Bromine is very corrosive. A lighted taper burns for a few moments in its vapor, with a flame green at its base, and red at the top, and is then extinguished. It is soluble in water, alcohol, and ether; the latter is the best solvent. With water at 32° Fahr., if forms a hydrate, in crystals of a fine red color. It gives to a solution of starch an orange color. Chlorine will displace it from all its combinations with hydrogen.

Chloride of Bromine.—Formed by transmitting a current of chlorine through bromine, and condensing the disengaged vapors by a freezing mixture. The factitious article is more simply formed, and is equally good as an accelerator, but not as quick. See page 25, Part I. M. Bissou, a Frenchman, found that the real chloride of bromine is so sensitive, that Daguerreotype proofs are taken by it in half a second. He succeeded in taking persons and animals in the act of walking.

Bromic Acid may be obtained by pouring sulphuric acid upon a dilute solution of bromide of baryta, and evaporating. No interest.

Bromide of Baryta.—Boil of protobromide of iron with moist carbonate of baryta; carefully evaporate and it will crystallize in white rhombic prisms, which have a bitter taste, are slightly deliquescent, and soluble in water and alcohol.

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.