34 Mr. H. A. Newton on certain recent 



The oxide of indium, dried and placed in a porcelain crucible, 

 is reduced by hydrogen or by coal-gas, and the metal melted 

 under a layer of cyanide of potassium. 



The metal is white, with a shade like that of platinum ; it is 

 extremely soft and ductile; its specific gravity at 20° C. is 7'15, 

 and its equivalent =35*9 (H = l). The hydrated oxide is com- 

 pletely precipitated from its solutions by ammonia and by pot- 

 ash ; the presence of tartaric acid prevents this precipitation. 



The oxide is of a dark brown while hot, but of a straw-colour 

 when cool. Sulphuretted hydrogen precipitates very little in- 

 dium from a concentrated acid solution ; it is, however, precipi- 

 tated in great part from very weak and slightly acid solutions : 

 the precipitation is almost complete in the acetic solution. Sul- 

 phuret of indium is of a beautiful yellow colour like that of sul- 

 phuret of cadmium. 



The salts of indium are colourless. The chloride obtained by 

 passing chlorine over heated oxide is extremely volatile ; it gives 

 colourless crystalline plates, and is extremely hygroscopic. 



The spectrum of indium, which led to the discovery of the 

 metal, has two lines : — one of a deep blue ; the other weaker, in 

 the violet. 



V. On certain recent Contributions to Astro-Meteorology. 

 By H. A. Newton*. 



1. Radiant-Points, or Radiant Areas. 



FOR more than twenty years a Committee of the British As- 

 sociation for the Advancement of Science has annually 

 made an extended report on tl Observations of Luminous Me- 

 teors/ 5 in which have been given in detail the times, paths, 

 physical appearances, and other phenomena of meteors seen 

 during the years immediately preceding. No special effort has 

 been made until recently to elaborate this mass of material. 

 R. P. Greg, Esq., of Manchester, assisted by Mr. A. S. Her- 

 schel, at last undertook the task of plotting the paths contained 

 in the voluminous records. By this means they have determined 

 between fifty and sixty radiants for different periods of the 

 year. Professor E. Heis of Minister has in like manner, from 

 observations made by himself and his assistants during a pe- 

 riod of twelve years, deduced a similar and, to a considerable 

 extent, a corresponding series of radiant-points. The latter 

 series is in the Monthly Notices of the Royal Astronomical 

 Society, vol. xxiv. p. 213. Both series are in the Report of the 

 British Association for 1864, and in the Proceedings of the Bri- 

 tish Meteorological Society for January 18, 1865. Prom the 

 latter source we give the following Table : — 



* From Sillhnan's American Journal for Mav 1867. 



