Physics and Chemistry. 411 
Volatile on the platinum wire. The chlorplatinate RbCl, PtCl, is a bright 
yellow, anhydrous, sandy powder, consisting of microscopic regular octa- 
edra, which can only be distinguished from the chlorplatinate of potas- 
sium by its lesser solubility. 
The second of the new elements, the authors term Cesium, from 
Cesius, sky blue; it gives a beautiful and highly characteristic spectral 
ine, lying near the strontium-line Sré. It appears to constant! y accom- 
Out the carbonate of cxsium with absolute alcohol. To remove the last 
traces of potassium and rubidium, about ¢ths of the carbonate are ren- 
dered caustic by baryta water, the mass evaporated in a silver dish, and 
carbonate forms indistinct erystals, soluble in five times their weight of 
absolute alcohol, deliquescent and very caustic. The bicarbonate forms 
Permanent, glassy prismatic crystals. The nitrate is anhydrous an 
1somorphous with nitrate of rubidium. The sulphate is also anhydrous 
and permanent in air; it forms a well crystallized alum and double 
KO, SO,+ ~6HO. r 
crystallizes in cubes and is deliquescent in the air; it is slightly volatile 
and easily becomes somewhat basic, when heated in air. The chlorpla- 
tinate forms bright yellow microscopic regular octahedra, and is the least 
Soluble of the three alkaline double chlorids—Ann. der Chemie und 
Pharmacie, exix, 107. 
3. Probable existence of a new Element.—Crookes has proposed the 
name Thalium for what appears to be a new element existing In certain 
Thallium appears to be a dense brown powder characterized in a very re- 
