NOTES. 



287 



Inquiry into Human Nature," which was 

 composed during his residence in Ceylon, 

 from 1840 to 1842. 



It has been remarked that the destruc- 

 tive 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 Lon- 

 don " Spectator," that the fact may be satis- 

 factorily explained by the law that the press- 

 ure, 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. 



J. F. JcLiTTS Schmidt, 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 con- 

 nected with several observatories in Ger- 

 many 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 in- 

 vestigated the volcanic phenomena at San- 

 torin, 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. 



Hann, 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 diame- 

 ter 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. 



An International Forestry Exposition is 

 to be opened this year in Edinburgh. It 

 will be devoted to the exhibition of the for- 

 est-products of the whole earth, and will be 

 open to all nations. 



Professor Heinrich Carl Berghacs, a 

 distinguished German geographer, cartog- 

 rapher, and historiographer, died in Stet- 

 tin, February lYth, 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 

 test, a physical atlas of ninety-three maps ; 

 of numerous important works on geography; 

 of many commimications to the German 

 scientific papers and departments ; and of a 

 text-book of geography, which, translated 

 into the vernacular languages, ia in use in 

 schools in India. 



The death of Dr. J. Todhunter, an emi- 

 nent mathematician and author of text- 

 books, is announced. 



Captain Neils Hoffmeter, 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 meteorologi- 

 cal stations in Greenland and Iceland, and 

 was Secretary of the International Polar 

 Commission. 



M. Jean Baptiste Dcmas, the distin- 

 guished French chemist, died April 11th, in 

 the eighty-fourth year of his age. Since 1823 

 he has been constantly adding to our knowl- 

 edge of organic chemistry. His theory of 

 substitution and his treatise on chemistry 

 as applied to the arts were important con- 

 tributions to the science. He has been at 

 different times a member of the National 

 Assembly, Minister of Agriculture and Com- 

 merce, and Vice-President of the Senate, of 

 France. In 1868 he became Permanent Sec- 

 retary 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" (Decem- 

 ber, 1880). 



Drs. Ferrier and Gerald Yeo commu- 

 nicated a paper to a recent meeting of the 

 Royal Society on the effects of lesions of 

 different regions of the cerebral hemi- 

 spheres. They described experiments con- 

 ducted upon monkeys, in which they re- 

 moved, under anaesthetics, certain limited 

 areas of the cortex ; the results of the ex- 

 periments went to confirm in a very exact 

 manner most of the conclusions previously 

 arrived at by Dr. Ferrier and by neuropa- 

 thologists. The locaUzation of the centers 

 of sight and hearing and the effect of remov- 

 ing portions of the brain in producing anaes- 

 thesia on the opposite side of the body 

 were thus tested. 



Dr. Wilson, 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. 



