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Review of .4merica?i Chemical Research.
and washed with nitric acid. This filter is especially applicable for manganese dioxide and ammonium phosphomolybdate. T h e work with them is as accurate as with paper, much more rapid, and less expensive. A Ilethod for Cleansing Burettes. Note. By W. GLESN. J . Am. Chenz. Soc., 21, 3?2.-The method consists in the use of chromic acid. T h e reviewer having used this method for t h e last fifteen years can attest its efficacy, if the acid be concentrated (see alsoTalbot, Quant. --2?zabsi.r, p. 5s ( 1 8 9 7 ) ,and]. j r a k t . Chem., 79, 1 1 7 ) .
INORGANIC CH EM ISTRY. HESKI
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On an Isomer of Potassium Ferricyanide. BY J A l t E S LOCKE AND GASTON H. EDWARDS.&d?n. Chent. ]., 21, 193--206.-By treating potassium f e r r i q a n i d e with potassium chlorate and hydrochloric acid Skraup obtained a red solution from which, by repeated precipitations with alcohol, lie obtained an amorphous, hygroscopic powder, to which he assigned the formula K,Fe( C N ) l, although he was not able to prepare it in pure condition. T h e authors, by modifying Skraup's conditions, have been able to obtain a pure crystallized product, Potassium ferricyanide was heated to 95' C. with hydrochloric acid and potassium chlorate until effervescence began. T h e solution mas cooled to 2 0 3 and filtered ; and to the cool filtrate slightly less than an equal volume of alcohol was added. This produced a heavy crystalline precipitate. By partial reprecipitation the crystals were obtained pure, and on analysis were shown to have the composition represented by t h e formula K,Fe(CN)n.H,O. T h e substance is an isomer of potassium ferricyanide, and the authors propose to name it potassiuni p ferricyanide. Like the ordinary salt, this isomer yields characteristic precipitates with the solutions of the heavy metals. These have, in general, the same characteristics a s the salts of the normal ferricyanide, and in some cases pass over into the latter with extreme ease. T h e precipitate of the /3-ferricyanide with silver nitrate is dark-brown and flocculent, and when heated in its mother-liquor to 100' passes over into the bright-orange of the a-ferricyanide. T h e potassium &ferricyanide can readily be distinguished from t h e normal ferricyanide by the fact that with bismuth nitrate solutions it does not form a precipitate while the a-ferricyanide produces an insoluble straw-colored precipitate. Stannic chloride, on the other hand, yields no precipitate with potassium a-ferricyanide, but precipitates the isomer completely. No explanation of the isonierism is offered.
Inorganic Chemistry.
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On the Formation of Potassium p-Ferricyanide through the Action of Acids upon the Normal Ferricyanide. BY JAMES LOCKEAND GASTONH. EDWARDS. .4m. G e m . ] . , 21, 413418.-It has been shown that the conversion of potassium ferricyanide into potassium P-ferricyanide can be accomplished by any acid, the presence of potassium chlorate not being necessary, a s was assumed in a previous paper. Potassium ferricyanide was treated with hydrochloric acid, and from time to time portions were drawn off and precipitated with bismuth nitrate. Subsequently, the percentages of cyanogen which these precipitates contained were determined by reduction with sodium amalgam and titration to potassium a-ferricyanide. T h e rate of conversion from p- to @-ferricyanidebrought about by the catalytic action of acids seems to be directly proportional to the degree of ionization of the acid. The Action of Metals on Nitric Acid. BY PAULC. FREER GEORGE0 . HIGLEY.A m . Ckem. /., 21, 377-3p.--In previous papers the action of copper, lead, and silver on nitric acid of different strengths has been described. I n this research the action of iron on nitric acid, and the effect of electrolytic hydrogen on it, using kathodes of copper, silver, and lead, have been investigated. When iron is dissolved in nitric acid, the reduction-products are nitrogen dioxide, nitric oxide, nitrous oxide, and ammonia. With acid of specific gravity 1.40nitrogen dioxide and nitric oxide are obtained in proportions varying with the amounts of solvent. These differences caused by using varying amounts of solvent led the authors to the view that nitric oxide is solely a secondary product of the decomposition of the dioxide by water. As the acid diminishes in strength the variation in the relative amounts of these two products is much like that observed with copper, silver, and lead, until a specific gravity of 1 - 3 0is reached when nitrous oxide is formed. With acid having a specific gravity of I .25 the reaction is further complicated by the appearance of nitrogen and ammonia, the former reaching a maximum at 1 . 1 5 and then falling off, while the latter rises to a maximum a t 1.05. With platinum electrodes, electrolytic hydrogen acts upon concentrated nitric acid much the same a s do copper, silver, and iron, nitrogen dioxide being the principal product. Nitric oxide is produced with acid of specific gravity 1.35,and hydrogen begins to be liberated when acid of 1.30 sp. gr. is used. Small amounts of ammonia are formed only with dilute acid. T h e activity of electrolytic hydrogen depends, in a marked degree, upon the character of the electrode upon whose surface it is liberated. When nitric acid having a specific gravity of 1.05 is subjected to electrolysis in cells having kathodes of silver and lead, respectively, on the AND
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Review of American Chemical Research.
surface of which kathodes there is equal current density, the reduction-products are the same ; i. e . , nitrogen and ammonia i n approximately the same proportions. On the other hand, copper, when made t h e kathode of an electrolytic cell containing acid of the same strength, has a much greater energizing effect upon the hydrogen deposited upon its surface than is shown by lead under the same circumstances, and produces about three times a s much ammonia as the latter. Since in the electrolysis of nitric acid the action of the metallic ions is excluded, and the reduction must be effected by t h e hydrogen in contact with t h e surface of the different metals, it follows that the widely different results obtained when lead and silver dissolve in nitric acid cannot be attributed to the hydrogen atoms alone, but must also involve the direct deoxidizing effect of the metals themselves. With concentrated, non-ionized acid the metals alone cause the change, but on dilution both metals and hydrogen cause it. Preparation of Metallic Tellurium. BY VICTORLENHER. J . A m . Chenz. Sac., 21, 347-3j1.-The author has tried the different methods for the extraction of metallic tellurium from t h e slimes of the Baltimore Copper Works, and concludes that I ‘ reducing sugars will give a very practical method for the preparation of metallic tellurium.” Action of Hypophosphorous Acid upon ilolybdic Acid. BY CLARENCZEBACGH X X D EDGAR F. SMITH. /. A m . Chenz. Sac., 21, 354-386.-X tenth-normal solution of molybdenum trioxide was reduced by hypophosphorous acid both in the presence of a definite excess of that acid and in t h e presence of sulphuric acid. T h e reduction is approximately to the oxide Mo,O,. Neutral solutions are not reduced. New Method for the Preparation of Cesium. BY HUGOERDMANS A N D A . E.MENKE. J . A m . Chevz. SOL.,21, 2j9-262.Alinost the theoretical yield of cesium was obtained by heating cesium hydroxide with magnesium powder in a red-hot tube, through which a current of hydrogen was passing. The Specific Gravity of Cesium. BY A . E. MENKE. J . Am. Chem. Soc. , 21,.420-42 I .-Not less than four grams of metal were weighed first, in hydrogen, then under liquid paraffin. T h e mean of six determinations gives the value 2.400 for the specific gravity . The Solubility in Water of Certain Natural Silicates. BY GEORGE STEIGER.J . A m . Chem. Sac., 21, 437-43g.-Certain silicates were found to give up alkali on long standing with water. T h e amount of alkali which went into solution was determined by means of standardized hydrochloric acid, using methyl o,range a s indicator.
