Chemistry and Physics. 463 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Radio-active Lead. — It was recently mentioned in this 

 Journal (this vol., p. 235) that Hofmann and Stkauss had 

 obtained, according to the usual analytical methods, from the 

 minerals pitchblende, broggerite, uranium mica, and samarskite, 

 a radio-active lead sulphate which loses its activity after several 

 months, but regains it under the influence of cathode rays. These 

 investigators have now published a description of a continuation 

 of their work. In their previous article they mentioned the fact 

 that by the fractional crystallization of the lead chloride prepared 

 from the active sulphate a more soluble portion was obtained 

 which appeared to contain a new radio-active element, but it now 

 appears that while a substance with unusual chemical properties 

 may thus be obtained from pitchblende (but not from brogger- 

 ite), this supposed new element has no radio-active properties. 

 The authors believe, however, that there is another new element 

 in the more soluble fractions obtained from lead chloride, but 

 they admit that it approaches lead in its properties much more 

 closely than the other one, and now they are not certain that this 

 substance is the cause of the radio-activity. While the previous 

 article raised the hope that a definite radio-active element would 

 be obtained, the present article is disappointing in regard to the 

 matter. As far as the supposed new elements are concerned, 

 they would be interesting as such, even without possessing the 

 power to emit Becquerel's rays ; but so many mixtures have 

 heretofore been brought forward as elements that one is inclined 

 to be skeptical about such announcements. — JBerichte, xxxiv, 907. 



h. l. w. 



2. The Zirconia of Euxenite from Brevig. — The discoveries of 

 new elements are usually rare occurrences in the present period 

 of chemical development, but now, in addition to the supposed 

 new elements from pitchblende and broggerite that have been 

 mentioned in the preceding notice, an unknown element, or two, 

 from euxenite is announced from the same laboratory in Munich. 

 In extracting the small amount of lead from euxenite Hofmann 

 and Pkandtl treated the sulphuric acid residue with " basic " 

 ammonium tartrate and obtained in solution not only lead, but 

 titanium and zirconium. The latter possessed properties which 

 made the presence of an unknown oxide seem probable, and by a 

 series of operations an oxide was obtained which appeared to the 

 investigators to be practically free from all previously known 

 substances. It is distinguished from zirconia in being precipi- 

 tated by an excess of ammonium carbonate and in giving no tur- 

 meric reaction. The authors say that it gives no precipitate with 

 oxalic acid, " even when the mineral acid has been previously 



