January 14, 1892] 



NATURE 



263 



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 i2ZnS,H._,S 

 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 constitu- 

 tion 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 the absence of a membrane. Arsenious 

 sulphide may exist in "solution" in three distinct types of sub- 

 division. 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 solu- 

 tion. — Solution and pseudo solution, Part I., by H. Picton 

 and S. E. Linden The authors consider that there is a con- 

 tinuous 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 

 panicles 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 solu- 

 tion, 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-solulions to crystallizable solu- 

 tions. This property consists in the repulsion of the dissolved 

 substance as a whole from one of the electrodes of a battery 

 dmmersed 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 deter- 

 mining the amount of acidity of the solution. The author con- 

 cludes 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. Sulphur- 

 ous 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 a and )3 modifications of chloro- 

 benzene hexachloride, by F. E. Matthews. A mixture of these 



NO. 



1159, VOL. 45] 



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 I : 3 : 4:5 tetrachlorobenzene. The /3 modification of chloro- 

 benzene hexachloride, CgHsCly, melts at about 260°, and is more 

 stable and less volatile with steam than the o compound, which 

 melts at about 146°. — The sulphochlorides of the isomeric 

 dibromonaphthalenes, 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 dichloroderivatives, 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 di- 

 bromonaphthalenesulphochlorides may be prepared by simply 

 boiling them with dehydrated alcohol.— The aciion of bromine 

 on o and /8 bromonaphlhalene, by H. E. Armstrong and E. C. 

 Rossiter. The authors have succeeded in resolving into its con- 

 stituents 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-a- 

 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, 

 CgHj^O, 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 CgHj^O, but probably C10HJ2O. — 

 Metaxylenesulphonic acids. Part II., by G. T. Moody. When 

 acetmetaxylid {1:3:4) is sulphonated, metaxylidinesulphonic 

 acid (Mca : NHj : SO3H = I : 3 : 4 : 6) is obtained in slender 

 needles soluble' in water. On diazotizing, and boiling with 

 alcohol, it yields ethoxymetaxylenesulphonic acid ; if the diazo- 

 compound 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 ethoxy-acids are also described, together 

 with tetramethylene, methyl, and ethyl ketones and their reduction 

 products. 



Geological Society, December 23, 1891.— W. H. Hudle- 

 ston, F.R.S., Vice-President, in the chair.— The following 

 communications were read : — On part of the pelvis of Pola- 

 canthtis, by R. Lydekker.— On the gravels on the south of the 

 Thames from Guildford to Newbury, by Horace W. Monckton. 

 The author stated that the greater part of the hill-gravel in the 

 district referred to belonged to the Southeru Drift of Prof. 

 Prestwich, and that the valley-gravels for the most part consisted 

 of material derived from the Southern Drift. Small patches of 

 Westleton Shingle and Glacial Gravel occurred near Reading 

 and Twyford. He divided the Southern Drift into three classes: — 

 (i) Upper Hale type, characterized by the abundance of small 

 quartz pebbles and the scarcity of chert. (2) Chobham Ridges 

 type, with abundance both of small quartz pebbles and chert. 

 (3) Silchester type ; quartz scarce, and chert very rare or alto- 

 gether absent. He described the localities at which these types 

 occurred and their limits of distribution, and then referred to the 

 Glacial Gravels of the Tilehurst plateau, which he believed to 

 have been deposited before the excavation of the valley of the 

 Thames between Reading and Goring. The author then dealt 

 with the valley-gravels, which he believed to be mainly derived 

 from the hill-gravels of the immediate neighbourhood, and 

 showed how the various types of hill-gravel had contributed 



