510 Scientific Intelligence. 



glass flask into which a large quantity of emanation was introduced 

 and allowed it to decay there spontaneously. In four such experi- 

 ments lithium was detected in the solutions, while blank experi- 

 ments in which no emanation was used gave no indications of 

 lithium. The experiments were then repeated with every possible 

 precaution. It was found to be extremely difficult to get chemical 

 products free from lithium. It is present in distilled water, and 

 almost all reagents ; and if a reagent does not contain it, and is 

 allowed to remain some time in a glass vessel, it is then found to 

 contain traces of the element. Water which had been distilled 

 from platinum and gave no test for lithium upon evaporation, 

 gave a distinct spectroscopic test for that element after it had 

 stood for 24 hours in a glass flask. It was found that fused 

 quartz also contains lithium, and therefore platinum was selected 

 as the material in which the careful experiments were carried out. 

 As a result of these experiments the investigators were unable to 

 find any indication of the production of lithium by the action of 

 radium emanation upon solutions of copper salts, and therefore 

 they could not confirm Ramsay and Cameron's results. — Comp- 

 tes, Rendns, cxlvii, 345. h. l. w. 



3. The Formation of Mists in Presence of Radium Ema- 

 nation. — Mdme. Curie showed some time ago that the presence 

 of radium emanation causes the condensation of saturant or non- 

 saturant water vapor as well as other vapors. This condensation 

 is manifested by the formation of a persistent mist, visible by the 

 light of an electric arc. Upon further study it is the author's 

 opinion that chemical compounds capable of absorbing water 

 vapor until drops are formed are produced under the action of 

 the emanation. The mists are persistent and may last more than 

 a month, and they disappear gradually as the emanation decays. 

 With pure water and air charged with emanation, a slight mist 

 lasting some days is observed. If the air is replaced by carbon 

 dioxide, no persistent mist is observed. But if instead of pure 

 water a mixture of equal weights of water and sulphuric acid is 

 used, a dense, persistent mist is obtained. A very persistent mist 

 is produced in the presence of concentrated sulphuric acid and 

 carbon dioxide. It was found that a flask containing water and 

 air charged with the emanation gave a much more dense mist 

 when closed with a rubber stopper than when sealed up, and 

 when a piece of sulphur was placed in the air in a similar sealed 

 flask the amount of mist was increased, while traces of sulphuric 

 acid could afterwards be detected in the water. Mists which 

 were very intense at first and lasted more than a month were 

 observed with petroleum ether and with carbon disulphide in the 

 presence of air charged with emanation. Anhydrous ether in 

 presence of carbon dioxide and the emanation also gave a persist- 

 ent mist. Experiments with certain solids showed that in the 

 presence of emanation, iodine and carbon dioxide as well as cam- 

 phor and air gave dense mists of long duration. A mist may 

 be observed with actinium in the presence of water and carbon 



