of oxygen is a mixture of the oxides of nitrogen. Now, after having served for over a century as the only process capable of being used on a manufacturing scale, it is likely to be replaced by what seems to be a simple one, although there is no difference in the fundamental chemical reaction. It merely replaces the gaseous carrier of oxygen by a solid contact, which by its catalytic action brings about the same change of sulphur dioxide to sulphur trioxide, with this advantage, however, that these solid contact substances, acting at a higher temperature, can bring about the change in the absence of water and thus produce at once a stronger acid than chamber acid, or even sulphuric anhydride itself as a direct product. But while this catalytic action of a solid body in the formation of sulphuric acid has long been known and recognized, the difficulties in the way of the industrial application have hitherto been so great that it was considered impracticable to compete with the chamber process. After the expenditure of an immense amount of time, patience and money, the Badische Anilin und Soda Fabrik have now devised a method which they have applied so successfully that they have been enabled to increase the output of the anhydride from 18,500 tons in 1888 to 116,000 tons in 1900. In the absence of exact details, withheld, it may suffice here to say, that the sulphur furnace gases are employed. These, contrary to Winkler's view, may be diluted with nitrogen without interference with the reaction, but the presence of even small quantities of solid impurities, such as antimony, bismuth, lead, zinc, etc., acts injuriously; the most injurious of all solid substances, however, is arsenic, even traces of this element being sufficient to injure the contact mass. In the process developed, these impurities have been carefully and absolutely eliminated. This is accomplished by methods of cooling and washing, and particularly by causing the gases to traverse a long distance before they reach the contact mass. The sulphur trioxide here formed, is rapidly absorbed in a vessel containing 97 to 98 per cent. sulphuric acid, and from this removed from time to time, either as pure trioxide, or after the addition of water, to produce sulphuric acid of any concentration, or mixture of the acid and sulphur trioxide in all proportions. The contact mass that has been found most suitable, fulfilling all necessary conditions, is platinum. The incentive to the development of this practical contact process was the need of anhydrous or fuming sulphuric acid for the cheaper manufacture of products like alizarine, and especially the new synthetic indigo, but the process is able to compete advantageously with the chamber process for all grades of sulphuric acid. -Amer. Jour. Pharm., June, 1902, 285-289.

SELENIUM.

Selenium Hydride-Preparation and Properties.-De Forcrand and Fonzes Discon obtain perfectly pure H,Se by the action of water on aluminum selenide, and if the latter be in excess, the gas is slowly evolved

free from moisture. Thus obtained it boils at -42° C., and a little below -40° C. condenses to a colorless liquid which solidifies at 64° C. The density of the gas at 42° C. is 2.12. It is very soluble in water, 3.31 volumes dissolving in one volume of that liquid at normal atmospheric pressure at 13.2° C., 3.77 volumes at 4° C., and 2.7 volumes at 22.5° C.Pharm. Journ., Mar. 15, 1902, 213; from Comptes rend., 134, 171.

Selenic Acid Action on Gold.- Victor Lehner found pure selenic acid, HSEO,, obtained by decomposing lead selenate with HS and concentrating by evaporation, to be without action on gold in the cold, but that hot concentrated selenic acid readily dissolves the metal. The action begins at 230° C., but proceeds more rapidly at 300° C., SeO, being evolved and Au,3SeO, formed. It occurs in very small yellow crystals, insoluble in water but soluble in hot H¿SeO,, so that it may be precipitated from solution in that acid by the addition of water. The reaction is similar to that of H2SO, on copper, and is the first recorded instance of the solution of gold in a simple oxy-acid.—Journ. Amer. Chem. Soc., 24, 355.

PHOSPHORUS.

Red Phosphorus-A Product of Polymerization.—The investigations of R. Schenk lead him to the conviction that red phosphorus must be regarded as being a product of the polymerization of white phosphorus ; the allotropy of phosphorus consists of a polymery, not of a polymorphy. The investigations, however, do not lead to the conclusion that the formula. of red phosphorus is P.; it is assumed that preliminarily a very loose compound P, is found, and that this rapidly acquires a higher polymerization. —Pharm. Ztg., March 26, 1902, 240; from Ber. d. D. Chem. Ges.

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Phosphorous Oxide-Conditions of Formation.-A. Besson has obtained phosphorous oxide, PO, as follows: Hydrobromic acid gas is dissolved in pure cold phosphoryl chloride, and through this a current of PH, gas is passed; phosphonium bromide is formed, accompanied by the deposit of a small quantity of yellowish solid. By gently raising the temperature above 50° C., and keeping the whole on the water-bath for some hours, a voluminous precipitate forms, which can be separated out by filtration. This precipitate, after precipitation, was found to have the composition PO.-Chem. News, July 19, 1901; from Compt. rend., 1901, No. 25.

Hypophosphites-Ammonium Molybdate Test Liable to Fallacy.-The ammonium molybdate test for the presence of hypophosphites, which was originally recommended by Millard, is directed to be made by adding ordinary nitric solution of ammonium molybdate to a hypophosphite solution, and then a little sulphurous acid. A blue color is said to result, or, in very dilute solutions, a blue color dependent on shaking or gently warming. F. A. Upsher Smith, however, states that it is noteworthy that water acidulated with hydrochloric or sulphuric acid gives with ammonium molybdate a faint indication of blue which might be mistaken for traces of

a hypophosphite. Still more important is it to note that sulphurous acid solution gives a blue color with a solution of ammonium molybdate. It should not, therefore, be used in performing the test. Again, a solution of a hypophosphite gives with ammonium molybdate solution a blue color, without warming, if left standing over night.-Pharm. Journ., Feb. 22, 1902, 143.

Referring to the above criticism of the ammonium molybdate test for hypophosphites, E. J. Millard states that the test is reliable if carried out. under the conditions originally mentioned by him. The strongly aeid reagent is prepared as follows: Dissolve I part of molybdic acid in 4 parts of solution of ammonia B. P., and pour into 15 parts of nitric acid of specific gravity 1.2. The solution gradually deposits, and the clear liquid can be poured off. If this solution be employed in testing hypophosphites or hypophosphorous acid, there is no difficulty in obtaining the blue precipitate or color when a few drops of sulphurous acid are subsequently added. With this solution no color is given on the addition of diluted hydrochloric or sulphuric acids, as stated by Mr. Smith to occur with ammonium molybdate, nor does sulphurous acid alone give with this solution a blue color. That it gives a blue color with a hypophosphite on standing for some hours is correct, but the addition of sulphurous acid develops the color immediately. Mr. Millard adds, for the purpose of clearness, that he finds the best proportions for the tests are as follows: 0.1 Gm. of a hypophosphite dissolved in 2 Cc. of water, add 1 Cc. of the strong nitric acid solution of molybdate and 2 drops of sulphurous acid. An immediate blue color occurs, rapidly turning into a heavy precipitate. An excess or deficiency of the test solution is to be avoided, as, although a coloration appears, it becomes brown or colorless more or less quickly on standing. The delicacy of the test is well shown by dissolving o.1 Gm. of sodium hypophosphite in 100 Cc. of water. 2 Cc. of this solution, representing 0.002 Gm. of the salt, to which 2 drops of the reagent is added, and 2 drops of sulphurous acid, will develop a deep blue color on heating. The tests for hypophosphites are not sufficiently numerous or characteristic that we can afford to do away with one that is both distinctive, rapid and accurate.-Ibid., Mar. 8, 1902, 201.

Commercial Meta-Phosphoric Acid-Monosodic Diortho-Phosphate an Impurity.-H. Giran finds that the crystals which appear in the sticks of commercial metaphosphoric acid kept in imperfectly closed bottles are composed of a new sodium hydrogen phosphate, NaH,PO,, and not, as stated by E. Zettnow, a peculiar variety of pyrophosphoric acid. The composition of the sticks themselves is found to correspond with the formula NaPO3 + HPO3, which, by combining each with one molecule of H2O, give the new salt NaH¿P2O, or, it may be, a combination of H¿PO and NaH2PO-Pharm. Journ., April 19, 1902, 313; from Compt. rend., 134, 711.

Meta-Phosphoric Acid-A Valuable Reagent for the Detection of Albumen in Urine.-Which see under "Organic Chemistry."

Sesquisodic Phosphate-Question of Existence. From the fact that when orthophosphoric acid is titrated with alkali, helianthin turns from red to yellow when one equivalent of soda has been added, litmus changes with 1.5 equivalents, and phenophthalein with two equivalents, H. Joulie concluded that a sesquisodic phosphate, Na,H,PO, must exist, intermediate between the monosodic phosphate, as shown by helianthin, and the ordinary disodic phosphate. He found, in fact, that by adding sufficient orthophosphoric acid to crystals of that salt to render it neutral to litmus, a great lowering of temperature took place; on concentrating, crystals were obtained, consisting of oblique prisms which, after drying, responded to the formula Na,H,PO. This salt is stated to be much more suitable for therapeutic use than ordinary disodic phosphate, since it is more soluble, is active in smaller quantities, being tonic in doses of 15 grains, laxative with 75 grains, and purgative with 150 grains. Its taste is saline, neutral, and scarcely unpleasant. Although the author describes it as a new salt, J. B. Senderens points out, in a subsequent communication, that it has previously been described by himself and Filhol, and that, if dried in vacuo over H2SO,, it contains 3 molecules of H2O; when exposed to a current of dry air at ordinary temperature it retains 15 molecules of water of crystallization.-Pharm. Journ., June 27, 1902, 549; from Comptes rend., 134, 604 and 713.

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Sodium Phosphate-Examination for Arsenic.-Frederick T. Gordon, in response to a query," has made an examination of six different samples of sodium phosphate procured in retail stores in order to verify the presence or absence of arsenic in them. He found them to be free from arsenic by the U. S. P. tests, but two of them showed traces of this element by the methods of Dowzard and Cady (see Proceedings, 1901, 794) for the detection of arsenic in glucose and sodium phosphate. The reduction and mercuric chloride test-paper method was found to be quite delicate and satisfactory.-Proc. Pa. Pharm. Assoc., 1901, 121, 122.

Calcium Phosphate-Examination of Commercial Samples.-Frederick T. Gordon has subjected nine samples of precipitated calcium phosphate, procured at retail stores, and three samples direct from jobber's packages, to examination in order to reply to a "query" concerning the commercial quality of this compound. Among these only one sample failed to come up to the U. S. P. requirements; it contained about 20 per cent. of calcium sulphate. Minute quantities of arsenic were found in two samples. -Proc. Pa. Pharm. Assoc., 1901, 120.

Calcium Phosphate-Adulteration with Calcium Carbonate.-Lyman F. Kebler notes an adulteration of calcium phosphate with calcium carbonate to the extent of 30 per cent.-an adulteration which in some operations,

such as the preparation of laudanum, for instance, would cause an endless amount of trouble.-Amer. Journ. Pharm., Jan., 1902, 13.

Bicalcic Phosphate-Solubility.-The constants of solubility of different phosphates of lime being very incomplete and even contradictcry, A. Rindell has undertaken the investigation of the subject by modern methods. He employed a very pure salt, finely pulverized, and having the following composition: CaO, 32.70; PO, 41.30; H2O, 26.20 per cent. The numbers obtained show clearly (1) that the concentration of the solution increases with the time and the mass of the salt in contact with a given volume of water; (2) the quantity R at first differing but slightly from unity increases with the concentration.-Chem. News, Feb. 7, 1902, 71; from Compt. rend., Jan. 13, 1902.

Manganic Phosphates-Formation and Composition.-V. Anger has investigated the components of the violet solution which forms the product of fusion of manganese nitrate and phosphoric acid heated to about 210° C. The molten mass, when dissolved in water and left for some days, deposits a rose-colored crystalline crust, manifestly a mixture of two or three pro

Herrmann analyzed a portion of this crust and found it correspond to the formula Mn,PO.8H2O. The author isolates from the same mass a hydrated salt in a pure state, and finds it to have a formula differing from Herrmann's only in the amount of water of crystallization, Mn ̧Ð ̧О21-14H,O. The salt is certainly a pyrophosphate, for when treated in the cold by an alkali, it gives an alkaline phosphate which possesses all the reactions of pyrophosphoric acid. Manganic metaphosphate, MnPO,, was also isolated from the crust and found to be anhydrous.-Chem. News., Aug. 2, 1901, 60; from Compt. rend., July 8, 1901.

Phosphorus Sesquisulphide-Failure to React with Mitscherlich's TestE. G. Clayton has examined various specimens of commercial phosphorus sesquisulphide, and applied Mitscherlich's test to each in the following way: 20 Gm. of the compound was distilled with 100 Cc. of 10 per cent. sulphuric acid in an egg-shaped flask connected with a spiral condenser, the operation being conducted in a dark room. The very small amount of light emitted by the lamp was screened from the condenser and receiver, which were in complete darkness. In each case 40 Cc. of liquid was distilled over. The results with comparatively pure specimens were absolutely negative, not the faintest luminosity being perceptible in any part of the apparatus, and it is said to be evident that pure, or even approximately pure, phosphorus sesquisulphide gives no reaction with Mitscherlich's test, though very crude specimens of phosphorus sesquisulphide no doubt occasioually give Mitscherlich's reaction. The author is now conducting some experiments with the object of discovering whether exposure and keeping can so induce partial oxidation in, or alter the composition of pure, or nearly pure, phosphorus sesquisulphide as to impart to it after a time the property of giving Mitscherlich's reaction.