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Rh Inquiry into Human Nature," which was composed during his residence in Ceylon, from 1840 to 1842.

has been remarked that the destructive force of a tropical hurricane appears to be greater than the velocity of the wind will account for, when compared with the velocity of an ordinary head gale. Mr. Joseph John Murphy suggests, in the London "Spectator," that the fact may be satisfactorily explained by the law that the pressure, and consequently the destructive force of any current, whether of air or water, is proportional, not to the velocity, but to the square of the velocity; so that, if the velocity is doubled, the destructive force is increased fourfold.

, Director of the Observatory at Athens, Greece, died in that city late in February, aged fifty-eight years. He was a German by birth, and was connected with several observatories in Germany before he was called to Athens in 1858. One of his most important works is his map of the moon, which embodies the results of thirty-five years of work. He investigated the volcanic phenomena at Santorin, and composed a work on volcanoes. He studied earthquakes and the relations of the moon to them, and, in meteorology, he published a study on the duration of the twilight.

, of Vienna, objects to the theory that the eruption of Krakatoa filled the air with dust enough to cause red lights all over the world, on account of the quantity of dust it would take. He calculates that the volume of Krakatoa, supposing it to be 822 metres high and four kilometres in diameter at the base, was 13,780 cubic kilometres. Supposing it all to be reduced to dust and scattered over the earth, it would form a thickness of only three hundredths of a millimetre. At a height of ten miles above the surface, the dust-stratum would be still thinner. Herr Hann does not seem to have taken into consideration the fact that the dust came from the bowels of the earth and not from the volcano alone; and he may not have made sufficient allowance for the extremely attenuated condition in which it was.

International Forestry Exposition is to be opened this year in Edinburgh. It will be devoted to the exhibition of the forest-products of the whole earth, and will be open to all nations.

, a distinguished German geographer, cartographer, and historiographer, died in Stettin, February 17th, in his eighty-seventh year. Besides his work on general atlases and many special maps, he was the author of the best map of the Iberian Peninsula, of an atlas of Asia with fifteen maps and text, a physical atlas of ninety-three maps; of numerous important works on geography; of many communications to the German scientific papers and departments; and of a text-book of geography, which, translated into the vernacular languages, is in use in schools in India.

death of Dr. J. Todhunter, an eminent mathematician and author of text-books, is announced.

, Director of the Meteorological Institute of Copenhagen since 1872, has recently died. He was the author of an important paper on the storms of the Northern Atlantic; published for three years a daily synoptical weather-chart; prompted the establishment of meteorological stations in Greenland and Iceland, and was Secretary of the International Polar Commission.

, the distinguished French chemist, died April 11th, in the eighty-fourth year of his age. Since 1823 he has been constantly adding to our knowledge of organic chemistry. His theory of substitution and his treatise on chemistry as applied to the arts were important contributions to the science. He has been at different times a member of the National Assembly, Minister of Agriculture and Commerce, and Vice-President of the Senate, of France. In 1868 he became Permanent Secretary of the French Academy of Sciences. A portrait and biographical sketch of M. Dumas were given in vol. xviii, p. 257, of "The Popular Science Monthly" (December, 1880).

and Gerald Yeo communicated a paper to a recent meeting of the Royal Society on the effects of lesions of different regions of the cerebral hemispheres. They described experiments conducted upon monkeys, in which they removed, under anæsthetics, certain limited areas of the cortex; the results of the experiments went to confirm in a very exact manner most of the conclusions previously arrived at by Dr. Ferrier and by neuropathologists. The localization of the centers of sight and hearing and the effect of removing portions of the brain in producing anæsthesia on the opposite side of the body were thus tested.

, of England, has tried to count the number of hairs on the human head. Taking a fairly hirsute head, he found the number of hairs on a square inch of surface to be 1,066. This, he estimated, would give 127,920 for the whole head. More thickly-clad heads might have 150,000 hairs.