586 



SCIENCE. 



[N. S. Vol. VIII. No. 200. 



following fluorin and preceding sodium in 

 the periodic table. Its refractivity is low, 

 being 0.3071 compared with air, that of 

 helium being 0.1238 and that of argon 

 0.958. Its spectrum is characterized by 

 brilliant lines in the red, the orange and 

 the yellow, also two lines in the green. 



In the last fractions of liquid argon Pro- 

 fessor Ramsay finds three new gases, one of 

 them not previously described. These are 

 krypton, which had previously been ob- 

 tained from liquid air and characterized by 

 two very brilliant lines, one in the yellow 

 and one in the green; metargon, which 

 shows a spectrum closely resembling that of 

 carbon monoxid, but characterized by its 

 inertness, not being changed by sparking 

 with oxygen in the presence of caustic 

 potash ; and a still heavier gas, not hitherto 

 described, which Professor Ramsay calls 

 xenon — the stranger. This gas possesses a 

 much higher boiling point than the others 

 and is easily separated, but is present in 

 only minute quantity. Its spectrum is 

 analogous to that of argon, but differs in 

 the position of the lines. The quantity of 

 neon present in the atmosphere is estimated 

 as one part in 40.000, and that of the other 

 gases at even less. 



MoissAN has described, in the Cmnptes 

 Mendus, a hydrid of calcium of the formula 

 CaHj, formed by heating crystallized cal- 

 cium in a stream of dry hydrogen. It is a 

 hard, white crystalline body, stable in dry 

 air, even at a red heat, but burning before 

 the oxy-hydrogen flame. At ordinary tem- 

 peratures it is not very reactive, but when 

 heated reacts readily with most of the 

 negative elements. It is a powerful reduc- 

 ing agent, decomposing cold water with 

 great violence, with the formation of cal- 

 cium hydroxide and liberation of hydrogen. 

 In this hydrid the hydrogen thus seems to 

 resemble the carbon in calcium carbid and 

 the phosphorus in calcium phosphid. 



How much need there is of a careful re- 

 vision of much of our knowledge regarding 

 inorganic compounds is well illustrated by 

 two investigations in the last Berichte. 

 Muthmann and ]Sragel,in studying the lower 

 oxidation stage of molybdenum, show that 

 the supposed monoxid MoO has no exist- 

 ence, but is really Mo(OH)3. They also 

 confirm Blomstrand's conjecture that the 

 supposed dichlorid MoCJ^ is in reality 

 MOjClg. They proved its formula by de- 

 termining its molecular weight by the boil- 

 ing-point method. 



From the days of Berzelius the dark pre- 

 cipitate formed by alkaline stannous chlorid 

 in a bismuth solution has been considered 

 to be a monoxid of the formula BiO. 

 Vanino and Treubert show conclusively 

 that this precipitate is in reality metallic 

 bismuth with more or less BijOj, and that 

 BiO cannot be formed in the wet way. 



According to Engineering aluminum is 

 being introduced into India as a substitute 

 for copper and brass in the manufacture of 

 cooking utensils. Professor Chatterton, of 

 the Madras University, commenced experi- 

 ments with the metal-working classes of 

 the School of Arts, and a little later a small 

 factory was equipped whose output is now 

 over a ton a month. The vessels have 

 been very favorably received, which is very 

 remarkable considering the conservatism of 

 India. It is necessary, however, that the 

 vessels should be the exact counterparts of 

 the copper and brass vessels previously in 

 use, and they must be hand-made and not 

 spun. Efforts are being made to establish 

 similar factories elsewhere than at Madras. 



Three papers by Professor Vezes have 

 recently appeared in the Prods Verbaux, of 

 the Societe des Sciences Physiques et Natu- 

 relles de Bordeaux, which should be noted. 

 The first is on the double oxalates of plat- 

 inum and palladium. The platoxalates have 

 been long known, but obtained by a rather 



