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smaller quantities of nitric oxide. The acid, acting upon zinc or mercury in the presence of ammonic nitrate, yields little gas but nitrogen; with silver, nitric, but no nitrons oxide is also formed.—21 A, September, 1875.

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CONSTITUTION OF PHOSPHORUS OXYCHLORIDE. The constitution of phosphorus oxychloride has long been a matter of discussion. Ira Remsen now shows that the compound may be formed by the direct action of ozone upon the trichloride. This fact strengthens the view which regards phosphorus as pentatomic, and obliges us to look upon the atom of oxygen in the oxychloride as directly satisfying the two bonds of affinity left free in the trichloride.—4 D, July.

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DISCOVERY OF VANADIC ACID IN MAGNETIC IRON. Dr. Isidor Walz communicated to the American Chemical Society, May 4th, that he had discovered 0.3 to 0.4 per cent. of vapadic acid in magnetic iron ores from the Church Mine, New Jersey. Apart from the scientific interest attaching to the rich occurrence of that rare metal on our soil, this discovery may lead to important practical results, as the salts of vanadium have recently begun to play an important role in the preparation of aniline black, indelible marking-ink, etc., and the supply has hitherto come from much poorer sources than the one now disclosed.

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CARBON FROM THE ROOF OF A GAS-RETORT. Mr. A. McDougall exhibited before the Manchester Literary and Philosophical Society a specimen of carbon obtained from the roof of a gas-retort, resembling graphite in its almost metallic lustre. It was undoubtedly produced by the decomposition of the hydrocarbon gases in the intense heat of the retort; and it is suggested that its formation may throw some light on that of graphite, as that substance is always associated with rocks that have been subjected to igneous action.–18 A, April 9, 1875, 89.

LIQUID CARBON DIOXIDE IN MINERAL CAVITIES. W.Noel Hartley, examining the liquid which occasionally occurs in the cavities of quartz, has corroborated the conclusions of Davy and Brewster with regard to its being lique

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fied carbon dioxide. He noted that at the temperature of about 31° Centigrade the liquid in such a cavity disappeared entirely, to return upon cooling. Dr. Andrews gives 30.92° Centigrade as the critical temperature of carbon dioxide, so that there can no longer be any doubt concerning the nature of the liquid under examination.—1 A, March 26.

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CARBON MONOSULPHIDE. Sidot finds that when carbon disulphide, inclosed in hermetically sealed tubes, is exposed for about two months to the action of sunlight, brown flakes of the new monosulphide, CS, are deposited. This substance, dried and purified, is a chestnut-brown, tasteless, odorless powder of 1.66 specific gravity. It is insoluble in water, alcohol, turpentine, or benzol; boiling ether or carbon disulphide dissolves traces of it. Hot nitric acid dissolves the monosulphide to a red liquid; but chlorohydric acid is without action upon it. A boiling solution of caustic potash takes it up freely, forming a blackish brown liquid, from which acids reprecipitate the substance. At 200°. Centigrade the new sulphide decomposes, sulphur distilling off, and carbon remaining behind.—18 C, 1875, September 29.

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A NEW CLASS OF CYANIDES.
Gaston Bong, studying potassium ferrocyanide and some
of its derivatives, has obtained a remarkable new double salt.
It is formed by treating a mixture of the common yellow
prussiate and potassium chlorate with sulphuric acid until a
persistent blue color is produced. The resulting mass is
heated gently,extracted with water, neutralized with sodium
carbonate, boiled and filtered. This solution, by careful
crystallization in vacuo, yields black crystals, which, readily
soluble in water, give it an intense violet color. The com-
pound may be regarded as the type of an entirely new class
of double cyanides, and its relation to well-known ferro-
and ferricyanides may be indicated by formula :
Potassium ferrocyanide...

.K,FeCy,
Potassium ferricyanide.

...K, Fe,Cy.
New compound ....

K,Fe, Cy12 Thus, in this series, every added potassium atom needs a doubling of all the other atoms in the molecule. The new

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soda

salt is a powerful oxidizing agent, and produces greenish precipitates with metallic solutions.Bull. Soc. Chimique, 1875, October 5.

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IMPROVEMENT IN THE AMMONIA-SODA PROCESS. The following improvement in the ammonia process for the manufacture of soda has been patented in England. The solution of chloride of ammonium formed is mixed with carbonate of magnesia and distilled, and the carbonate of ammonia, which passes over, is again used in the manufacture of soda. The solution of chloride of magnesium remaining, which also contains some chloride of sodium, originally present with the chloride of ammonium, is concentrated, and the chloride of sodium removed from time to time as it crystallizes out. What remains is then calcined with the formation of hydrochloric acid and magnesia. The latter is reconverted into carbonate by the gaseous products of combustion from the furnace. The separation of the chloride of sodium before the calcining is important, as otherwise the chloride of magnesium will not be decomposed by heat alone. A partial decomposition of the chloride of magnesium, however, is said to be more favorable to the conversion into carbonate than complete decomposition.—5 C, XXXVIII., 1875, 303.

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MANUFACTURE OF SODA FROM SEA-WEED, Herland, in Comptes Rendus, calls attention to some defects in the treatment of sea-weed for the manufacture of soda, and makes some suggestions for an improvement of the process. IIe remarks that in the ordinary method the weeds destined to be calcined are dried on the shore in the open air, involving decomposition and a loss of salts by moisture, and that the process of incineration is itself de. fective. The method by which he proposes to remedy the difficulty is as follows: Place the fresh weed in baskets of iron wire, moved by a turning crane, and steeped in a series of vats containing about fifty kilogrammes of good quicklime per cubic meter, and so placed that it can pass in succession from vat to vat until it is exhausted of its useful salts. The time of steeping in each vat is from forty to sixty minutes. The successive saturated lyes are to be reduced to dryness and treated with carbonate of potash. This will yield &

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soda very rich in soluble salts and alkaline iodides. While the incineration gives but fifteen per cent. of potash and one per cent. of iodide, the new process yields forty to fifty per cent. of potash, and sometimes six per cent. of iodide. The residual weeds are applicable to agricultural purposes.-14, July 21, 1876, 32.

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ATOMIC WEIGHT OF CERIUM. Bührig, by means of a series of careful combustions of cerium oxalate, bas very accurately redetermined the atomic weight of the metal. This, based upon the values given by Stas for carbon and oxygen, he finds to be 94.1782. This value is the mean of results obtained in fifteen experiments. - Journal für prakt. Chemie, XII., 209.

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THE CERIUM METALS.

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The rare metals cerium, lanthanum, and didymium have at last had their atomic weights definitely fixed by Hillebrand. He determined the specific heat of each metal by means of Bunsen's ice calorimeter, getting the following values: Cerium, 0.04479; lanthanum, 0.04485; didymium, 0.04563. These figures, considered with reference to Dulong and Petit's law, correspond respectively to the atomic weights 138, 139, and 144.78. These observations prove that the lower oxides of these metals are really sesquioxides, and the higher oxides, dioxides. Until lately the atomic weights of this

group have been rated at only two thirds of the above values.- Poggendorff"': Annalen, 1876, No. 5.

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CERIUM, LANTHANUM, AND DIDYMIUM. These rare metals have recently been isolated in quantity by Drs. Hillebrand and Norton, students under Bunsen at Heidelberg. Cerium outwardly resembles iron, is very ductile and malleable, and tarnishes readily. In hardness it about equals silver, and its melting point is at a full red heat. Heated in the air it kindles very easily, at a lower temperature even than magnesium, burning with great brilliancy. Upon shaving a cerium wire with a knife the thin fragments of metal ignite as they are cast off, while with an ordinary fire-steel sparks can be struck from it as from a flint. Didymium and lanthanum resemble cerium closely, but are ess inflammable, and do not tarnish so easily. The specific grayities are as follows: Cerium, 6.628 to 6.728; lanthanum, 6.049 to 6.163; didymium, 6.544. In their electrical relations the three metals lie between magnesium and zinc; they are electro-positive to the latter, electro-negative to the former.Poggendorff"'s Annalen, March 25, 1875.

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EXPERIMENTS ON STEEL. MM. Trève and Durassier have communicated to the French Academy the following results of their investigations into the relation existing between the chemical and physical properties of steel. They prepared fifteen bars of steel, divided into five series of three bars, each series being of a different degree of carburation, and each tempered in a different manner. These bars were then magnetized to saturation, and their magnetic force determined by the method of deflection. The bar containing 0.95 per cent of carbon, and tempered with cold water, caused the maximum of deflection, represented by 47. The bar containing the same amount of carbon, but tempered with oil at 10° Centigrade (50° Fahr.), gave 43. That the magnetic capacity of steel is influenced by the nature of the liquid used for tempering seems therefore to be manifest. The bar containing 0.25 per cent. of carbon gave a deflection represented by 13, showing how decided is the influence which it exerts. In preparing diagrams of variations for the different series of bars, the influence of the percentage of carbon and of the tempering liquid became manifest. It was remarked, however, that at the top of the scale in carbon, the nature of the tempering liquid no longer exerted a very marked influence. The study of these diagrams brought to light, likewise, the noteworthy fact that a remarkable similarity existed between the magnetic curves and the curves of elasticity of the bars. The investigators assert from their experimental trials that carbon gives elasticity to the steel, and at the same time enhances its capacity for magnetism.---3 A, V., 556.

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VFLUENCE OF FOREIGN INGREDIENTS UPON THE PHYSICAL

PROPERTIES OF STEEL.
verience that has of late been gained in the pro-

hosphuretted steel may be characterized as a

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