Intelligence and Miscellaneous Articles. 389 



cur when those bases are present, with which thorina forms double salts; 

 the latter are but little precipitated by heat. It differs from .ilumina 

 and glucina, because it is insoluble in caustic potash, which dissolves 

 those substances ; from yttria, because it forms a double salt with sul- 

 phate of potash, which is insoluble in a saturated solution of sulphate 

 of potash : this circumstance furnishes a method of separating it from 

 yttria. It differs from zirconia, because the latter, after having been 

 precipitated hot by sulphate of potash, is for the most part insoluble 

 in water and the acids, and because thorina is precipitated by ferro- 

 cyanate of potash, and zirconia is not. It differs from the oxide of 

 cerium, in not assuming the same colour when it is dried and burnt, 

 and also in not giving with the blowpipe a coloured compound with 

 salt of phosphorus, or borax, either hot or cold, provided it be not at 

 all mixed with iron. 



From titanic acid it is distinguished by its precipitation with sulphate 

 of potash, or by the characteristic manner of that acid with the blow- 

 pipe. 



From the metallic oxides, properly so called, and with which there 

 is some inducement to place it on account of its great specific gravity, 

 it is distinguished by not being precipitated with sulphuretted hy- 

 drogen. — Bibiiotheque Uiiiverselle, Dec. 1829. 



PREPARATION OF MAGNESIUM. 



M. Bussy has announced to the French Academy, that he has ob- 

 tained magnesium or the metallic base of magnesia, and he sent a 

 specimen of the metal ; it was procured by the decomposition of the 

 chloride by a process similar to that employed by M. Wohler. 



Magnesium has the following properties : — it is brilliant, silvery 

 white, ])erfectly ductile and malleable, fusible at a moderate tempera- 

 ture, like zinc, volatilized at a temperature a little higher than that 

 of its melting point, and like that metal condenses into small glo- 

 bules. It does not decompose water at common temperatures ; it 

 oxidizes at a high temperature, and is slowly converted into mag- 

 nesia, when in small masses j but when in filings, it burns with great 

 splendour, throwing out spaks, like iron in oxygen. 



M. Bussy is of opinion, that magnesium may be usefully employed 

 in the arts ; and he is occupied with endeavouring to find means of 

 procuring it in asim|)le and oeconomical manner.— Le Globe, 



NEW NATIVE CO.-MPOtJND OF CARBONATE OF LIME AND CARBO- 

 NATE or SODA. 



This mineral diffijrs from Gay-Lussite, which is a compound of 

 the same salts ; it was procured by M. Barruel at a mineral dealer's, 

 who did not know its origin. The structure of this substance is 

 laminated, has an easy threefold cleavage, and gives a rhomboid 

 similar to that of carbonate of lime, as nearly as could be discovered 

 by comparing the crystals of these two substances 



The fragments arc perfectly transparent; the lustre is vitreous, 

 resembling that of arragonite. It scratches carbonate of lime readily, 

 and arragonite with difficulty. Its sp gr. is '2 921, and the double 



refraction 



