210 Chemical Notices : — M. Lamy on Thallium. 



that water was formed by heating the disengaged oxygen. But 

 by effecting the decomposition in a large vessel containing acidu- 

 lated water in w r hich the positive electrode was placed, and a 

 large porous cell filled with sulphate of copper in which the ne- 

 gative electrode was placed, so that there was no disengagement 

 of hydrogen, there was not the smallest trace of water in the 

 oxygen after its passage through the heated tube. I prove, then, 

 that in Baumert's experiment, as M. Marignac had supposed, 

 it is an imperfect separation of the gases which has led him to 

 a conclusion different from that usually admitted. 



I continue to work at this subject, but I have thought that 

 these first results might possess some interest for you, and hence 

 I have taken the liberty of communicating them to you before 

 my investigation is terminated and ready for publication. 



XXX. Chemical Notices from Foreign Journals. 

 By E. Atkinson, Ph.D., F.C.S. 



[Continued from vol. xxiv. p. 531.] 



LAMY* has communicated the following additional observa- 

 tions on thallium. The metal has as little tenacity as malle- 

 ability; its density is 11*862, and its equivalent 204; its specific 

 heat, according to Regnaultf, is 0*03355. It is diamagnetic, 

 and a bad conductor of heat and electricity. The aqueous solu- 

 tions of its salts are precipitated neither by alkalies nor alkaline 

 carbonates, nor by dilute solution of red or yellow prussiate of 

 potash. Hydrochloric acid produces a white precipitate of diffi- 

 cultly soluble chloride; iodide of potassium and chloride of pla- 

 tinum yield a yellow iodide, and a double chloride still more 

 insoluble. 



Sulphuretted hydrogen produces no precipitate in acid solu- 

 tions, and only a partial one in neutral solutions ; it precipitates 

 the metal as black sulphide from alkaline solutions. Zinc pre- 

 cipitates the metal from its various solutions, in brilliant laminae. 



Thallium forms with oxygen two oxides. The protoxide is 

 soluble in water, which it renders alkaline and caustic ; it absorbs 

 carbonic acid from the air, forming a carbonate insoluble in 

 alcohol. In the solid state the oxide is yellow or black, accord- 

 ing as it is hydrated or not. Its colourless solution, evaporated 

 in vacuo, deposits long bundles of yellowish prismatic needles, 

 which blacken as evaporation proceeds, so that at a certain stage 

 of desiccation there is a curious mixture of yellow and black 

 crystals. The protoxide melts above 300° to a brown volatile 

 liquid which attacks porcelain, taking from it a portion of silica. 



* Comptes Rendus, December 8, 1862. f Ibid. December 16, 1862' 



