376 M. Caron on Calcium, 



necessary ; any of its salts, mixed with a mineral acid, will do 

 equally well. 



By double decomposition of the baryta salt with the corre- 

 sponding sulphates, Scheibler has obtained the magnesia, 

 copper, manganese, nickel, cobalt, zinc, and cadmium salts. 

 The stroutia and lime salts were obtained by treating their chlo- 

 rides with free metatungstic acid. 



Metatungstic ether was obtained by treating crystallized tung- 

 state'of silver with iodide of ethyle. Besides these tungstates 

 and metatungstates, the author has described some new com- 

 pounds of oxide of tungsten, obtained partly by new and partly 

 by known methods. 



TVohler* has described some new salts of suboxide of silver. 

 Molybdate of Suboxide of Silver, Ag 2 0, 2Mo0 3 , is a heavy, black, 

 lustrous powder consisting of well-defined regular octahedra. 

 It is obtained by dissolving molybdate of oxide of silver in strong 

 ammonia, and passing hydrogen gas through the solution. The 

 operation succeeds best when the temperature is about 90°. At 

 a higher temperature metallic silver is formed. 



Tungstate of Suboxide of Silver, Ag 2 0, 2 WO 3 , is prepared in 

 the same manner, and forms a black, crystalline, glittering 

 powder, the particles of which under the microscope appear to 

 possess rhombic faces. 



Chromate of Suboxide of Silver. — The reduction of ehromate 

 of silver is effected at the ordinary temperature ; but it is impos- 

 sible to obtain the suboxide salt pure, as it always contains an 

 admixture of metallic silver. 



The preparation of metallic calcium is effected by M. Caron 

 as follows f. 300 parts of fused and powdered chloride of cal- 

 cium are mixed with 400 parts of granulated zinc, and 100 parts 

 of sodium in pieces ; the whole is placed in a crucible heated to 

 redness ; when the action commences, the fire' is moderated so 

 as to prevent the volatilization of the zinc, but it is ultimately 

 raised as high as possible. 



In this manner a crystalline regulus is obtained containing 10 

 to 15 per cent, of calcium, the remainder being zinc and a 

 small quantity of iron. To obtain the calcium, this alloy is 

 heated in a carbon crucible in tolerably large pieces. The cal- 

 cium thus prepared contains traces of iron ; it is of a pale 

 yellowish colour; its density was found to be 1*6 to 1*8, but 

 this is somewhat too high.. It is not perceptibly volatile ; but 

 the zinc in volatilizing carries away traces of it. It keeps toler- 



* Liebig's Annalm, April 1860. 

 t Comptes Rendus, March 1860. 



