NOVEMBKB 27, 1896.] 



SCIENCE. 



791 



0.03 mm. in diameter, and another of 0.008 

 mm. The rotation was found to be 

 unchanged, and the conclusion reached is 

 that particles of sodium chlorate down to 

 0.004 mm. in diameter possess completely 

 the crystalline structure which is necessary 

 for circular polarization. In solution, how- 

 ever, sodium chlorate is perfectly inactive. 



The late determinations of the atomic 

 weight of tungsten by E. F. Smith have 

 given a number close to 184.9. More re- 

 cently (J. Prakt. Chem. 53: 288) Schneider 

 has repeated his earlier work which gave the 

 number 184.12 and now finds the atomic 

 weight to be 184.01. Schneider proved his 

 tungsten to be free from molybdenum, but 

 he used the same material as in his former 

 determinations. He attributes the larger 

 figure of Smith and others to the use of too 

 small quantities, thereby involving rela- 

 tively large errors. 



LoBRY DE Bruyn has succeeded in com- 

 pletely dehydrating hydrazin-hydrate by 

 means of barium oxid, a method unsuccess- 

 fully used by Curtius, and in the Eev. Trav. 

 Chim. Pays-Bas 15 : 174 describes the 

 properties of the free hydrazin, N^H^. 

 Hydrazin is a solid, melting at 1.4°C and 

 boiling at 113. 5°C at 761.5 mm. It is solu- 

 ble in alcohols, but only slightly so in 

 other organic solvents. It dissolves many 

 inorganic salts as sodium and potassium 

 chlorids and nitrates. It is a stronger base 

 than ammonia, liberating the latter from its 

 salts. It reacts energetically with chlorin, 

 bromin, iodin, sulfur and phosphorus, and 

 oxidizes slowly in the air. It is noteworthy 

 that the boiling point of free hydrazin, 113°, 

 is very close to that of hydrazin-hydrate, 

 119°. J. L. H. 



SCIENTIFIC NOTES AND NEWS. 

 Invitations have been sent for the opening 

 of the new halls of ethnology and vertebrate 

 paleontology of the American Museum of Nat- 

 ural History, New York. The reception will 



be held from two to three o'clock on Novem- 

 ber 30th. 



We learn from Nature that the Royal Society's 

 medals have this year been adjudicated by the 

 President and Council as follows : The Copley 

 medal to Prof. Carl Gegenbaur, For.Mem.E.S., 

 for his researches in comparative anatomy, and 

 especially in the history of the vertebrate skele- 

 ton; the Rumford medal to Prof. Philipp Len- 

 ard, and also to Prof. Wilhelm Conrad Rontgen, 

 for their investigation of the phenomena pro- 

 duced outside a highly exhausted vacuum tube 

 through which electrical discharge is taking 

 place; a Royal medal to Sir Archibald Geikie, 

 F.R.S., on account of the great value and im- 

 portance of his many original contributions to 

 geology; a Royal medal to Prof. Charles Ver- 

 non Boys, F.R.S., for his invention of quartz 

 fibres and investigation of their properties, his 

 improvement of the radiomicrometer and inves- 

 tigations with it, for developments in the art of 

 instantaneous photography, and for his deter- 

 mination of the value of the constant of attrac- 

 tion; The Davy medal to Prof. Henri Moissan 

 (of Paris), for the isolation of fluorine and the 

 use of the electric furnace in the preparation of 

 refractory metals; the Darwin medal to Prof. 

 Giovanbattista Grassi (of Rome), for his most im- 

 portant discoveries, especially on matters di- 

 rectly related to Darwin's speculations. Her 

 Majesty has signified her approval of the award 

 of the Royal medals. 



The Secretary of the Permanent Committee 

 of the International Zoological Congress an- 

 nounces the subjects for the two prizes, to be 

 awarded at the next Congress. These are : 'A 

 study of the ruminants of Central Asia, from 

 the points of view of zoology and geography ' 

 and ' An anatomical and zoological monograph 

 on some groups of marine invertebrates.' 

 The papers, which may be in manuscript or 

 printed since September, 1895, must be pre- 

 sented before May 1, 1898. They must be 

 written in French, which seems to be contrary 

 to the spirit of an international congress. It is 

 in any case doubtful whether many men of sci- 

 ence will care to compete for such prizes. "We 

 are somewhat vaguely informed that ' Les 

 prix consisteront, au choix des laur^ats, soit en 



