4. Some Experiments on the Molecular Refraction of Dissolved Electrolytes. By Dr. J. H. GLADSTONE, F.R.S., and W. HIBBERT. This was a preliminary notice of some experiments undertaken in the hope of throwing some further light on the nature of electrolytes in solution, and especially on the views advocated by Van t'Hoff, Ostwald, and Arrhenius. It was discovered many years ago that hydrochloric acid had an increased molecular refraction when it was dissolved in water, and it has been more recently observed that this increase has further augmented as the solution is made weaker. It was now found that on raising the temperature 55° there is a distinct reduction of the molecular refraction. This is scarcely what would be expected from an increase of ionic dissociation. It would appear that chloride of lithium follows the same law as hydrochloric acid in regard to the effect of dilution, but on raising the temperature it was found that the molecular refraction was slightly increased in strong solutions, but decidedly decreased in weak ones. Chloride of sodium shows much the same molecular refraction at different strengths and in different temperatures. Sulphate of magnesium was examined as a salt of a different type, but it closely resembled the sodium chloride. As the results obtained from these four electrolytes were so diverse no general conclusions were drawn. 5. The Action of Heat on Alkaline Hypochlorites. By Professor H. M. MCLEOD, F.R.S. 6. A Simple Apparatus for Storing Dry Gases. By W. SYMONS, F.C.S. A Requiring some dry carbonic acid gas and ammonia, with only very limited appliances at hand, the author was at a loss how to store them. A mercurial trough was out of the question. Ordinary petroleum as sold in the oil shops suggested itself. For this purpose a large wide-mouth bottle had inserted into its cork a short delivery tube with a tap, and a metal funnel, with a long metal tube reaching nearly to the bottom of the bottle, also with a tap below the funnel. This is to supply the petroleum. To increase the pressure the tube should be long enough above the bottle. A glass tube, open both ends, is inserted in the cork, as large as it can be, say 3-inch internal diameter, or more. This reaches to about half an inch from the bottom of the bottle. With the cork well secured by cement or varnish not acted on by petroleum, the bottle can be filled with petroleum through the funnel, both taps being open. When full they are closed. glass siphon, with one end turned up and the other end a little enlarged to facilitate filling it with petroleum, is then inserted in the large tube, the finger being kept on the enlarged end so as to retain the petroleum while inserting it. If the whole be air-tight no petroleum will escape, and this will test the gasholder. Another tube, with the bottom turned, also fits into the large tube, and the bent end must be kept outside it, in the bottom of the bottle, so as to deliver the gas into the bottle. To the upper end of this tube is attached, by india-rubber tubing, the gas-generating apparatus, but with a small Woulfe's bottle intervening as a safely bottle to catch any petroleum which may be drawn over by any irregularity in generating the gas. Of course, the gas must also be passed through a drying apparatus. When sufficient gas has been collected, both tubes are withdrawn, and the gas stored for use. When required, petroleum must be put in the funnel, and the supply regulated by the tap. If the gas is to be stored for some time the siphon should remain in the gasholder, and the outer end of it be put into a bottle partially filled with petroleum to provide for the expansion or contraction of the gas by variations of temperature or atmospheric pressure. 1891. RR TUESDAY, AUGUST 25. The following Reports and Papers were read : 1. Report on Isomeric Naphthalene Derivatives. See Reports, p. 265. 2. Report on Wave-Length Tables of the Spectra of the Elements. 3. Report on the Absorption Spectra of Pure Compounds. 4. On the Specific Heat of Basalt. By W. C. ROBERTS-AUSten, C.B., F.R.S., and A. W. RÜCKER, F.R.S. Having been asked by the Rev. O. Fisher to determine for him the latent heat of basalt, we made some experiments on a specimen which was furnished to us by Professor Judd. Fragments of the rock were melted in a platinum crucible, the junction of a thermal couple consisting of platinum with platinum containing 10 per cent. of rhodium was immersed in the pasty mass, which was then allowed to cool. The scale of the galvanometer had previously been standardised by an observation on the solidifying point of pure gold, and this was repeated from time to time whilst the experiments were in progress. When the spot of light had reached the desired point, the wires were nipped off close to the basalt, and the crucible and its contents were plunged into 1,000 grammes of water contained in a silver calorimeter. The water was stirred by a screw or fan of silver, which was rotated by an electro-motor. The temperature was read by means of a mercurial thermometer which had been carefully corrected. The two main sources of error in the experiments are probably an uncertainty as to the mean temperature of the basaltic mass, owing to its being a bad conductor of heat, and the fact that in the processes of heating and cooling, it undergoes more or less important changes of constitution. The first error was reduced to small proportions by using small quantities of basalt, the most employed rarely much exceeding 20 grammes. The second error is in part unavoidable; the rapidly cooled basalt was always glazed like olivine. We also found that frequent heatings and coolings, and the nature of the flame, whether oxidising or reducing, employed to heat the mass, appeared to affect the results very seriously. In some experiments the crucible was heated in a small gas furnace, in others in a coke furnace. All the former were consistent with each other, and those of the latter group in which fresh specimens of basalt were used, were in agreement with them. The results obtained with specimens which had been heated two or more times in the coke furnace were, however, very irregular, and as we have not definitely proved what was the cause of these discrepancies, we publish our results with a certain amount of reserve. In the following table T is the temperature (Cent.) of the basalt at the moment of immersion, C is the mean specific heat between about 20° C. and T: If C12 be the mean specific heat between two temperatures t, and t2, we have the relation As Mr. Fisher was anxious to use our results in some calculations, we supplied him with approximate numbers before all our observations were completed. They do not, however, differ much from the above. The general result seems to be that the specific heat of basalt follows the ordinary rule that the specific heat of a substance is greater in the liquid than in the solid state. There is a large absorption of heat in the neighbourhood of 800°, which raises the mean specific heat between 750° and 880° to the large value of 0.626. 5. An Apparatus for Testing Safety Lamps. 6. On Didymium from different Sources. According to Kiesewetter and Krüss (Berichte, xxi., 2,313), a solution of the earths from Yttrotitanite from Arendal shows only three bands due to didymium. On examining a moderately concentrated solution after separation from the bulk of the other metals by precipitation with potassium sulphate, all the bands shown by an ordinary didymium solution of similar strength were seen. Specimens of didymium from Gadolinite, from Orthite, and from Monazite were also examined. No differences as compared with didymium from cerite could be observed sufficiently marked to justify the inference that the bands varied in strength in an independent manner. В в 2 7. On the Nature of Solution. By Professor W. RAMSAY, F.R.S. 8. The Interpretation of Certain Chemical Reactions. 9. Action of Nitrosyl Chloride on Unsaturated Carbon Compounds. The author, after mentioning the work done by Tilden with regard to the action of nitrosyl chloride on phenol and on the terpenes,' and also that of Tönnies on the action of the same reagent on amylene and anethol, gave a brief account of experiments, conducted by himself, on the action of nitrosyl chloride on the following substances: ethylene, propylene, amylene, cinnamene; crotonic, oleic, erucic, and cinnamic acids. Of these ethylene is chlorinated and forms the dichloride C,HCl,; propylene is practically unacted upon; amylene forms a nitroso-chloride, CHNOCI, melting at 152°; and cinnamene, a similar compound, CH,NOCI, melting at 97°. Crotonic acid is unacted upon even when heated to 90°, while oleic and erucic acids readily form definite nitroso-chlorides, the former melting at 86° and the latter at 92°. Cinnamic acid is unacted upon when cooled, but forms the dichloride C,H,O,Cl, when heated to 100°. The nitroso-chlorides are best prepared by dissolving the substance in chloroform, cooling to -10°, and then passing the nitrosyl chloride in until there is a strong smell of it. The chloroform is then evaporated off, and the nitroso-chloride recrystallised from alcohol or chloroform. These nitroso-chlorides are not merely molecular compounds, but definite and stable bodies undecomposed by alcohol or water. Up to the present the author can find no laws regulating the action of nitrosyl chloride on various carbon compounds, but he hopes to continue the work at some future date with that object in view. 10. On the Formation of Peaty Colouring Matters in Sewage by the Action of Micro-organisms. By W. E. ADENEY, F.I.C., Assoc.R.C.Sc.I., Curator, Royal University of Ireland. (Preliminary Notice.) The author gave a preliminary description of some experiments showing that when sewage is treated with a plentiful supply of nitre, and kept out of contact with fresh air, the soluble organic fermentable matters in it are completely destroyed by the influence of micro-organisms, without undergoing any intermediate stage of putrefaction, and that a liquid is finally obtained deeply coloured with a brown colouring matter, having similar properties to the colouring matters in natural peaty waters. The author also showed that the liquid, after the microorganisms have died down, probably contains no organic matter save the colouring matter referred to. 11. On a new Method of Disposal of Sewage, with some references to Schemes now in use. By C. G. MOOR, B.A. This paper is divided into three headings. The first gives the titles and objects of a few of the best known schemes, with some very short remarks as to how far their aims are accomplished. The second part deals with the method of utilisation of sludge, which the author has experimented on. He mentioned the important fact that the yield of ammonia amply pays the cost of this part of the process. 1 Journ. Chem. Soc. 27, 851 and 31, 554. The third part contains suggestions as to the lines on which one must work to obtain knowledge as to the best means of precipitation, with a view to subsequent utilisation. 12. The Reaction of Glycerides with Alcoholic Potash. 13. Note on the Electrolysis of Alloys. By HENRY C. JENKINS, The importance of the question as to whether alloys are capable of being electrolysed has for a long time been recognised, and has already been under the notice of a Committee of this Association. Several experimenters have endeavoured to separate the constituents of some alloys by this means, but hitherto no success in this direction has been recorded. Doubtless one reason of this negative result may be found in the difficulty of submitting a metallic bath to a sufficiently large difference of potential, owing to its very low resistance; but from the same cause there is another reason why electrolysis should not take place, at least in the case of the majority of alloys, a reason to which prominence does not hitherto seem to have been given. The variable polarisation, and the resistance of electrolytic baths generally, have led to the adoption of the view that in an electrolytic bath the electricity is conveyed by some method of convection or of successive molecular discharge, streams or chains of molecules carrying electrical charges from one electrode to the other. The bath itself is formed of some body whose resistance when pure is extremely high, so that it is usually necessary to add another body to it, an impurity, which probably acts by increasing the number of free molecules present. It is easy to imagine that in such an insulating medium molecules can be charged with electricity, which charge they can retain until they reach some body having a different potential to their own. But free molecules could not retain any charge if entirely within a conducting envelope, and in contact with it; and although the possibility of the possession of a gaseous envelope by the molecules forming a liquid has been recognised, still the conductivity of pure molten metals is scarcely in favour of any view that there is insulation between their molecules. If there were any considerable insulation it is difficult to account for the effects upon electrolytes of very small electro-motive forces, and it will be thus seen from these considerations that the want of success in the attempts to electrolyse alloys still leaves quite open the question of their constitution, whilst it is in full accordance with the conditions of Electrical Potential expressed by Laplace's equation. From the fact that alloys in many cases form true compounds, which may be obtained in a crystalline form if proper conditions are chosen, and because the conditions as to temperature of an electrolytic bath may be those most favourable for the precipitation of such a compound out of solution, it follows that all future electrolytic experiments with alloys should be made at temperatures sufficiently high to fuse any possible compounds, otherwise very deceptive results would be obtained, owing to the difficulty of correctly sampling the bath. |