American Journal of Science, October.—The standardisation of potassium permanganate in iron analysis, by Chailotte F. Roberts. A simple and rapid method for standardising a permanganate solution is to determine its strength, first, by comparison with electrolytic iron, and then by immediate titration with ferric chloride to determine the exact amount of iron in each cubic centimetre of the latter solution. This being ascertained, the ferric chloride solution can be employed at any time for the standardisation of potassium permanganate.—The detection and approximate estimation of minute quantities of arsenic in copper, by F. A. Gooch and H. P. Moseley. This is a modification of Sanger's process for wall-papers, whose application is rendered difficult by the fact that the presence of copper in the Marsh generator holds back the arsenic. The new process is based upon the simultaneous action of strong hydrochloric acid and potassium bromide upon the salt of arsenic.—Wave-lengths of electucity in iron wires, by C. E. St. John. A Lecher wire system was used in which the discs at the end towards the induction coil were left out, so as to obtain a form depending more directly upon the principle of electrical resonance. The indicator used was a bolometer as adapted by Rubens. It was found that the self-induction of iron circuits is greater than that of similar copper circuits under very rapid electric oscillations (115 million reversals per second). The difference in self-induction varies from 3˙4 to 4˙3 per cent., and increases with decreasing diameters. The increase in self-induction produces greater damping and a shortening of the wave-length of 1˙5 to 2 per cent. The permeability of annealed iron wires under this rate of alternation is about 385. For oscillations of the same period, the wave-length along parallel copper wires varies directly with the diameter of the wires, the maximum difference observed being 5 per cent, with wires of 0˙03915 and 0˙1201 cm. diameter respectively.— The present status of high-temperature research, by Carl Barus. To clear away the anomalies now existing in high temperature data, either the boiling point of zinc must come down from 930° to 905°, or else the melting points of gold, silver, and copper must move up 30° or 40°, or both must move towards each other by corresponding amounts.—The recent eruption in the crater of Kilauea, by L. A. Thurston. This is a description of the subsidence of the lava lake on July 11, when its level fell 250 feet.—On solutions of metallic silver, by M. Carey Lea. The solutions previously described are all colloidal, and at the same time absolutely transparent.