244 Scientific Intelligence. 



Since it seemed that water decomposed gold fluoride as soon as it 

 was formed, attempts were then made to carry out the same reac- 

 tion in the presence of anhydrous solvents, such as ether, chloro- 

 form, carbon tetrachloride, etc., hut the substances under experi- 

 ment were either insoluble in these solvents, or were decomposed 

 by them, so that this method did not succeed. Gold fluoride 

 appears, therefore, incapable of being formed by ordinary reac- 

 tions, although Moissan, by the action of fluorine gas upon gold 

 at a red heat, obtained a yellow, hygroscopic substance which 

 easily decomposed into the metal and fluorine. It is remarkable 

 that fluorine, the most active of all the elements, should have s<> 

 slight an affinity for gold. — Jour. Amer. Ohem. Soc. 9 xxv, 1 130. 



ii. l. w. 



3. The Separation of Madium from Barium. — Heretofore the 

 only available method for obtaining products richer in radium 

 from mixtures of barium and radium salts, has been the fractional 

 crystallization of the chlorides or the bromides. Marckwald 

 has now found that it is possible to obtain an enrichment in 

 radium by agitating a concentrated solution of the salts with one- 

 fifth of its weight of one per cent sodium amalgam. Barium and 

 radium amalgam is thus formed in which the proportion of 

 radium is much increased over that in the original mixture. By 

 repeating the operation with the residual liquid, after it has been 

 previously neutralized, successive products are obtained which 

 gradually diminish in activity. The method as thus employed 

 offers no advantages over the method of fractional crystalliza- 

 tion, since it also is a fractionating process, but it is interesting 

 in showing for the first time a difference in chemical behavior 

 between barium and radium. — JtericJite, xxxvii, 88. n. l. w. 



4. The Dissociation of the Alkaline Carbonates. — Having 

 previously shown that lithium carbonate can be completely volat i- 

 lized in a vacuum above 1000° in consequence of its dissociation 

 into carbon dioxide and lithium oxide, P. Lebeau has studied 

 the behavior of the carbonates of sodium, potassium, rubidium 

 and csesium under the same conditions. He has found that all of 

 these carbonates are dissociated above 800° with the formation of 

 carbon dioxide and a volatile alkaline oxide, so that a sort of 

 volatilization of the carbonates takes place. When the alkali 

 metals are divided into two sub-groups, lithium and sodium com- 

 prising the first, and potassium, rubidium and cesium the second, 

 it found that the ease of dissociation decreases with the atomic 

 weight in the first sub-group, and increases with it in the second. 

 — Cornptes Ilendus, exxxvii, 1255. n. L. w. 



5. Combination of /Saccharose witJi, Certain Metallic Salts. — 

 It is known that cane-sugar unites with sodium chloride, bromide 

 and iodide, as well as with potassium chloride, to form crystal- 

 line compounds. D. Gautmiku has recently succeeded in obtain- 

 ing a number of other similar compounds which are well-defined. 

 The following substances are described : 



