LONDON Chemical Society, December 16.—Prof. H. E. Roscoe, president, in the chair.—The following communications, &c., were made:—On the estimation of nitrogen by combustion, including the nitro-compounds, by J. Ruffle. The author recom mends the use of the following mixture instead of soda-lime in the process of Will and Varrentrapp:—Two molecules of sodium hydrate, one molecule of pure lime, and one molecule of sodium hyposulphite; the substance before burning being mixed with about, its own weight of a mixture of sulphur and wood charcoal. By this process good results were obtained with sodium nitrate, picric acid, &c.—Dr. Carnelly then showed some experiments as to the effect of pressure in raising the melting-points of ice, camphor, and mercuric chloride. By suspending a cylinder of ice (formed round the bulb of a thermometer) in a Torricellian vacuum and condensing the aqueous vapour by a freezing mixture, so as to keep the vacuum perfect, the author has raised ice to 180° C. before it melted. In the experiment shown, through an accident, the temperature only rose to 30° C. before the cylinder fell off the thermometer. Camphor which was boiling in a tube solidified when the pressure was diminished, though the heating was continued. Mercuric chloride, which under diminished pressure had been raised considerably above its melting-point, melted and boiled as soon as it was exposed to atmospheric pressure.—On some naphthalene derivatives, by Dr. Armstrong and Mr. Graham.