American Journal of Science, February.—The 27-day auroral period and the moon, by H. H. Clayton. Auroras were observed in 1895 on January 19, February 15, March 14, and April 10, with no intermediate cases. The probability of an accidental distribution in this manner is only 1 in 19,683. This period is probably due to the varying position of the moon north and south of the equator. When the moon's period is counted from its greatest northern position, there is a maximum on the 14th day, which coincides with the moon's greatest southern declination. There are minima on the 6th and 20th days, and a secondary maximum on the first day. The moon is an electrified body, charged negatively like the earth, and the potential gradient at the earth's surface depends upon the moon's position in the heavens.—Some products found in the hearth of an old furnace upon the dismantling of the Trethellan tinworks, Truro, Cornwall, by W. P. Headden. The ores smelted in this furnace for about 100 years were the usual Cornish tin ores carrying some arsenopyrite, which is cobaitiferous, and accounts for the cobalt in the samples. The chief products described are stannous sulphide, SnS, with some iron, a new iron arsenide, FeAs, an arsenide of tin, Sn6As, and stannic oxide, or an artificial “wood tin.” The latter was an irregular mass weighing about one and a half pounds. There was a central portion of metallic tin running lengthwise through the mass. It was probably formed by slow oxidation of a block of tin, but whether that was due to simple air and moisture or to other hot gases cannot now be determined.—Kant as a natural philosopher, by G. F. Becker. Kant's fame as a metaphysician has completely overshadowed his reputation as a physicist; but all his earlier papers were on physical subjects, such as the theory of winds, the earth's rotation period, the rings of Saturn, and, best-known, the nebular hypothesis of the universe. His great object in life was to discourage visionary speculation and to reduce all subjects to the confines of reason. Where Newton had in some cases to postulate the direct intervention of the Creator, Kant based his explanation upon known physical laws. If he had known the laws of thermodynamics, his nebular hypothesis, which only fell short in that respect, would have completely anticipated Laplace.—The islands and coral reefs of the Fiji group, by A. Agassiz. This is an extract from a letter dated Suva, Fiji Islands, December 15, 1897, describing a cruise in the Australasian twin-screw steamer Yaralla. The writer says: The great variety of causes which have been active in shaping the present physiognomy of the reefs and atolls of Fiji shows the impossibility of assigning any one factor, like subsidence for instance, as is done by Dana and Darwin, as the single cause for the formation of the many different kinds of atolls and barrier reefs to be found in the Fiji group. The formation of the great barrier reef of the southern shores of Viti Levu is due to causes very similar to those which have given to the northern coast of Cuba between Nuevitas and Matanzas its present physiognomy.