86
Review of American Chemical Research.
to prevent a rise in temperature, a reaction took place, which was complete in twenty-four hours. As the result, a well-crystallized compound of the formula Al,Cl,.z(C,H,),CCl was formed. This compound was decomposed by water, and when the temperature was kept a t oo, 97 per cent. of the theoretical yield, calculated from the carbon tetrachloride used, was obtained. In an attempt to make tetraphenylmethane, an ethereal solution of triphenylchlormethane and brombenzene was treated with sodium. Among the products of the reaction was a substance which resembled closely triphenylmethyl peroxide, which has recently been described by Gomberg (this Rev., 7, 6 ) . T h e authors propose to investigate the action of sodium on triphenylchlormethane,as preliminary experiments indicated that under certain circumstances these substances react, notwithstanding the fact that previous observers have found that they do not react.
On Triphenylchlormethane. BY M. GOMBERG. 1.Am. Chem. SOC.,23, 109-1 Io.-The author calls attention to the fact that his work on triphenylchlormethane, which has been recently published ( f h i s Rev., 7, 6 ) , was probably completed before the work mentioned in the preceding review mas begun. As stated above, Norris and Sanders found that sodium reacted with triphenylchlormethane. The author, in an earlier investigation, found that no reaction took place when these substances were brought together in benzene solution, and now expresses a regret that Norris and Sanders propose to investigate the subject farther, as he is continuing his investigations on triphenylmethyl. ANALYTICAL CH EnlSTRY. ULTIMATE ANALYSIS. H. P. TALBOT. REVIEWER.
The Composition and Analysis of London Purple. BY J . K. HAYWOOD. J. Am. Chenz. SOC., 22, 800-8Io.-Procedures are described for the determination of moisture, total arsenious and arsenic acids, total calcium, and also for soluble arsenious acid and soluble calcium, and other inorganic matters.” The author concludes that the arsenic and arsenious acids and calcium are usually combined as normal calcium arsenite and arsenate in the London purple, but that compounds corresponding to the symbols CaHAsO, and Ca,As,O, are occasionally present. ‘ I
Kilgore’s Modification of the Volumetric nethod of Estimating Phosphoric Acid. BY C. B. WILLIAXS.1. Am. Client. Soc., 23, 8-Iz.-The author finds the Kilgore procedure highly satisfactory, on the side of both rapidity and accuracy. T h e procedure is described in detail.
Geological and Mineralogical Chemistry.
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A Ilethod of Preparing Normal, Seminormal, Decinormal, Etc., Sulphuric Acid of Exact Strength. BY RICHARDK. MEADE. J. Am. Chem. SOC., 23, 12-15.-Pure, crystallized copper sulphate is dissolved in water, and the copper deposited upon a cathode of copper foil. The resulting solution of sulphuric acid, which was found to be free from copper after being subjected to a current of 1 . 5 amperes for eight hours, is diluted to the required volume. Soluble Arsenious Oxide in Paris Green. Preliminary Report. BY s. AVERYAND H. T. BEANS. .] Ana. Chem. SOC., 23, I I 1-1 17.-The authors find that the term " soluble arsenious oxide" as applied to Paris green is of doubtful significance, since the material, especially in a finely divided condition, undergoes hydrolysis when suspended in water, as a result of which arsenious acid passes into aqueous solution, the amount increasing to a maximum with the time of exposure. This point is ass q n e d to represent a state of equilibrium, but it is only reached after weeks of standing. Carbon dioxide is found to greatly promote the decomposition of the Paris green, and this constituent of the atmosphere may very well, under certain atmospheric conditions, cause a fair sample of the insecticide to exhibit the properties of a sample containing much more than the four per cent. of '' soluble arsenious acid," which is fixed upon as a maximum allowable quantity by Hilgard and others. Compare this Rev., 6, 168, and 7, 34.
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G EO LOG IC A L AND 11IN ERA LOG ICA L C H EM ISTRY. W.0 CROSBY.REVIEWER.
The Analyses of Italian Volcanic Rocks. BY H. S. WASHINGTON. A m . J . Sci., 159, 44-54.-Analyses are given of the following types of rocks : Ciminite, from Monte Cimino, Viterbo; Mica Trachyte (selagite), from Monte Catini, Tuscany ; Andesite, Radicofani, Tuscany ; Leucitite, from Capodi Bove, Alban Hills. A discussion is made of the analyses, the mineralogical composition of the rocks, and their classification in accordance therewith. Occurrence of Native Lead with Copper and Other Ilinerals at Franklin Furnace, N. J. BY W. M. FOOTE. A m . ] . Sci., 156, 187-188.-Small irregular masses of lead, I to z mm. in diameter, associated intimately with native copper and a variety of minerals-among them axinite, garnet, willemite, and phlogopite-have been found on a few specimens taken from the 800foot level of the Parker shaft on North Mine Hill. The rarity of native lead and its associations at Franklin make the discovery interesting.
