Societies and Academies.

Abstract

LONDON. Chemical Society, December 17, 1891.—Dr. W. H. Perkin, F.R.S., Vice-President, in the chair.—The following papers were read:—The composition of cooked vegetables, by Miss K. J. Williams. The vegetables examined after cooking were the artichoke (Jerusalem), broad bean, haricot bean, beetroot, cabbage, carrot, cauliflower, celery, cucumber, lettuce, mushroom, onion (Spanish), parsnip, pea (greeo), potato, radish, salsafy, scarlet-runner, sea-kale, spinach, tomato, turnip, and vegetable marrow. Ultimate analyses of the cooked vegetables were made, and their heats of combustion determined. The woody fibre, cellulose, fat, and the carbohydrates convertible into glucose were also estimated,—Metallic hydrosulphides, by S. E. Linder and H. Picton. The authors have investigated the sulphides of copper, mercury, arsenic, antimony, cadmium, zinc, bismuth, silver, indium, and gold; and find that, with the single exception of bismuth, all these metals form hydrosulphides of a more or less complicated character. These compounds, when treated with acids, in most cases lose part of their sulphuretted hydrogen, and form still more complicated hydro-sulphides. Copper forms a soluble hydrosulphide possessing the composition 7CuS,H2S; this, on treatment with acetic acid in presence of excess of sulphuretted hydrogen, yields a substance of the composition 9CuS,H2S; if no excess of sulphuretted hydrogen be present, the compound 22CuS,H2S is obtained. Hydrochloric acid produces still further condensation. Mercuric sulphide forms products approximately represented by the formulae 3IHgS,H2S and (2HgS,H2S. The latter formula represents the substance obtained in presence of acid, and is a very stable substance. Zinc sulphide solution.obtained from the hydroxide contains about 14 per cent, excess of sulphur as sulphuretted hydrogen; in presence of acetic acid a product represented approximately by-the formula 12ZnS,H2S Is obtained. The authors consider that their results support the conclusion that the metallic sulphides are in most cases poly-merides of very high molecular weight.—The physical constitution of some sulphide solutions, by H. Picton. The author has specially examined the solutions of mercuric, antimonious, and arsenious sulphides, and finds that in each case the sulphide is present in the form of very finely divided particles. In the “solution” of mercuric sulphide particles are visible under the microscope with a magnifying power of 1000 diameters, and are not diffusible even in Lhe absence of a membrane. Arsenious sulphide may exist in “solution” in three distinct types of subdivision. In the first solution, the particles are just visible. In the second, the particles are smaller but not diffusible, and scatter and polarize a beam of light sent through the solution. The third solution is diffusible in the absence of a membrane, but the optical behaviour shows that particles really exist in the solution.—Solution and pseudo-solution, Part I., by H. Picton and S. E. Linder. The authors consider that there is a continuous series of grades of solutions passing without break from a crystallizable solution to one containing the substance in a state of fine subdivision. They regard the very finely divided particles in the lower grades of solutions—colloid solutions—as large molecular aggregates retaining many of their molecular properties. On passing up through the different grades of solution, the particles become smaller, and the forces holding them in solution become more definitely those of chemical attraction. A new property is described, which holds for a large range of solutions extending from pseudo-solutions to crystallizable solutions. This property consists in the repulsion of the dissolved substance as a whole from one of the electrodes of a battery immersed in the solution. Thus, in the case of colloidal arsenic sulphide, the sulphide aggregates are repelled from the negative electrode; they are also repelled, though much less strongly, from the positive electrode. An exactly similar phenomenon is observed in the case of the crystallizable colouring-matter Magdala-red when dissolved in absolute alcohol, the repulsion being, however, from the positive electrode, no perceptible repulsion from the negative electrode being observable. This property is of much interest in itself, but also as exhibiting similarities between the different grades of solution.—The charge proceeding in an acidified solution of sodium thiosulphate when the products are retained within the system, by A. Colefax. The action of acids on sodium thiosulphate was investigated by allowing the action to proceed for a known time, then titrating with standard iodine solution, and subsequently determining the amount of acidity of the solution. The author concludes that the change proceeding in an acidified solution of sodium thiosulphate, when the products, viz. sulphurous acid and sulphur, are retained in the system, is a reversible one, a limit being reached a certain time from the time of acidification. The value of this limit is affected by the state of concentration, the ratio of the mass of acid relatively to the sodium thiosulphate, the nature of the acidifying acid, and the temperature. Sulphurous acid cannot prevent the decomposition of thiosulphuric acid. The presence of both products of the change in the system seems essential to the attainment of a limit value, for sulphurous acid, when initially free in the system at the time of acidification, has but little influence upon the values expressing the extent of the chemical change. A higher temperature favours the interaction of sulphurous acid and hydrogen and sodium thiosulphates; but this is a secondary change, which proceeds at lower temperatures with extreme slowness. Spring's statement that sodium trithio-nate is formed by the interaction of iodine, sodium sulphite, and sodium thiosulphate, seems to be wrong: the author finds that on adding a solution of these two salts to one of iodine no sodium trithionate is produced; the sodium sulphite is completely oxidized to sulphate.—The action of sulphurous acid on flowers of sulphur, by A. Colefax. Contrary to the statement of Debus, sulphurous acid acts on flowers of sulphur at the ordinary temperature, producing thiosulphuric acid and a polythionic acid, probably trithionic acid; no pentathionic acid was found. The action occurs even in the dark, and proceeds much more rapidly at a temperature of 80°–90°. Water has no action on flowers of sulphur, either at ordinary temperatures or at this higher temperature.—The α and β modifications of chlorofoenzene hexachloride, by F. E. Matthews. A mixture of these two substances with oily products is obtained by passing chlorine gas through chlorobenzene in presence of dilute caustic soda. They are both colourless crystalline substances, which on heating, either alone or with alcoholic potash, give a quantitative yield of 1:3:4:5 tetrachlorobenzene. The β modification of chlorobenzene hexachloride, C6H5Cl7, melts at about 260°, and is more stable and less volatile with steam than the a compound, which melts at about 146°.—The sulphochlorides of the isomeric dihromonaphthalenes, by H. E. Armstrong and E. C. Rossiter. The sulphochlorides of five of the dibromonaph-thalenes have been investigated. It is to be noted that, while the dibromonaphthalenes all have higher melting-points than the corresponding dichloro-derivatives, no such relation holds between the sulphochlorides of corresponding dichloro- and dibromonaphthalenes.—The action of alcohols on sulphonic chlorides as a means of producing ethereal salts of sulphonic acids, by H. E. Armstrong and E. C. Rossiter. The authors find that the ethereal salts of several but not all of the dibromonaphthalenesulphochlorides may be prepared by simply boiling them with dehydrated alcohol.—The action of bromine on α and β bromonaphthalene, by H. E. Armstrong and E. C. Rossiter. The authors have succeeded in resolving into its constituents the mixture of dibromonaphthalenes obtained on bro-minating naphthalene with two molecular proportions of bromine. —The action of bromine on a mixture of ortho- and paranitro-α-acenaphthalide, by H. E. Armstrong and E. C. Rossiter. When a mixture of ortho- and paranitro-acenaphthalides is brominated, the ortho-compound, not the para-, as previously supposed, is alone attacked.—Camphrone, a product of the action of dehydrating agents on camphor, by H. E. Armstrong and F. S. Kipping. Several chemists have described camphorone, C9H14O, as a product of the action of sulphuric acid on camphor; the properties of this substance, however, as given by different chemists, show great variations. The authors, on preparing the substance and purifying it by means of its hydrazone, find its composition to be, not C9H14O, but probably C10H12O.—Metaxylenesulphonic acids, Part II., by G. T. Moody. When acetmetaxylid (1:3:4) is sulphonated, metaxylidinesulphonic acid (Me2: NH2: SO3H = 1:3:4:6) is obtained in slender needles soluble in water. On diazotizing, and boiling with alcohol, it yields ethoxymetaxylenesulphonic acid; if the diazocompound be boiled with hydrobromic acid, the corresponding bromoxylene-sulphonic acid is obtained in slender needles. The salts of the above acids are described.—The action of propylene bromide on the sodium derivatives of ethylic acetoacetate and ethylic benzoylacetate, by W. H. Perkin, Jun., and J. Sten-house. The preparation and properties of the ethyl salts of acetylmethyltrimethylenecarboxylic acid, methyldiacetyldiadipic acid, and benzoylmethyltrimethylenecarboxylic acid, and their derivatives, are described.—Derivatives of tetramethylene, by W. H. Perkin, Jun., and W. Sinclair. The authors have prepared the monobromo-derivative of tetramethylenecarboxylic acid. Its hydroxy-, acetoxy-, and ethbxy-acids are also described, together with tetramethylene, methyl, and ethyl ketones and their reduction products.