Chemistry and Physics. 81 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Emaninm. — F. Giesel has obtained from pitchblende an 

 earth consisting chiefly of lanthanum which shows strong radio- 

 active properties. He finds that the behavior of the material is 

 different from that of radium, and believes that he has obtained 

 a new element which he calls emanium and which he hopes to 

 separate from lanthanum. The striking characteristic of this 

 material appears to be an emanation given off by it. When air 

 is blown through a flask containing preparations of the substance 

 enclosed in paper capsules, and the air issues from a tube against 

 a blende screen, a brilliant illumination is produced, and scintilla- 

 tions can be observed, even with the naked eye. The "sparks" 

 are more distinct and larger than those produced by radium or 

 polonium, and hence the material is more effective than these for 

 use in the spinthariscope. — Perichte, xxxvii, 1696. h. l. w. 



2. Radio-activity and Matter. — This topic has been recently 

 discussed by Professor Winkler, who is perhaps the most prom- 

 inent inorganic chemist in Germany. The great importance of 

 the recent discoveries connected with radio-active substances is 

 admitted, but the author doubts that the existence of new ele- 

 ments in this connection has been satisfactorily demonstrated. 

 He is inclined t© consider radio-activity as a purely physical pro- 

 cess, which, like magnetism, may act upon matter without affect- 

 ing its chemical nature. He points out that radium, which was 

 discovered nearly six years ago, is but slightly known in its 

 chemical relations, and that nothing can be stated about it in this 

 respect, except that it is remarkably similar to barium, but has 

 a higher atomic weight. The further chemical study of radium 

 and other radio-active substances is advocated, and the suggestion 

 is made that material for such work may be obtained from cer- 

 tain rocks, especially granites, occurring in Germany, which are 

 known to contain uranium minerals. — Berichte, xxxvii, 1655. 



H. L. W. 



3. Detection of Chlorides in the Presence of Bromides.— 

 Many methods have been proposed for the detection of small 

 quantities of chlorides in the presence of bromides in qualitative 

 analysis, but most of them present difficulties in the hands of 

 students. Chapman Jones has recently proposed for this pur- 

 pose the treatment of the mixed silver salts with a cold saturated 

 solution of ammonium bicarbonate. The reagent is poured over 

 the precipitate on the filter paper and is acidified with nitric acid 

 after it has run through. When the reagent is allowed to remain 

 in contact with silver salts for a few minutes with occasional 

 agitation, the precipitate produced by acidifying will be greater 

 in the case of the chloride, while the treatment of the bromide 

 may be continued sometimes for half an hour without giving a 

 positive result. In a case of doubt, the acidified liquid may be 



Am. Jour. Scl— Fourth Series, Vol. XVIII, No. 103.— July, 1904. 



