363 Analyfis of a Stone 



Chimie, No. 100. This earth, according to him, exifts in 

 the gadolinite in the proportion of 0*47 



Accompanied by filex — 0*25 

 Cxydofiron — — o - j8 



Alumine — — 0*04 



He defcribes alio fome of the properties polTefled by this 

 new earth when freed from all the bodies united to it in the 

 ftone, and which are as follows : — " All its combinations 

 with acids have a fweet tafte like that of the falts pf lead, 

 but a little more aftringent; with the fulphuric and acetip 

 acids it forms cryftallifable falts which do not change in the 

 air; with nitric acid it gives a radiating mafs, and with the 

 muriatic acid nothing that can cryftallife. 



Characlers of the Stone. 



ift, This fubftance has a black colour, and its duft is of a 

 blackifh gray. 



2d, Its fracture is absolutely vitreous, like that of glafs. 



3d, Its fpecific gravity, afeertained by Haiiy, is 4 - 0497- 



4th, It makes the magnetic needle move in a feniible 

 manner. 



5th, When expofed to the blow-pipe, it fplits into fmall 

 fragments, which fly to a confiderable dillance in bright red 

 fparks, which, when they detach themfelves, produce a ftrong 

 crackling noife. What remains of the (lone has a grayifli- 

 white colour, and does, not fufe completely. 



6th, When heated with borax it fuies, and communicates 

 to that fait a yellow colour inclining to violet. 



7th, A hundred parts of this fubltance, expofed to heat in 

 a platina crucible, loie eight parts of their weight, and the 

 matter aflumes ap ochry red colour. If, from the quantity 

 of iron it contains, we eflimate the oxygen it rauft abforb by 

 the operation, we (hall find that it has loft about \\ per cent. 



Phenomena which the Gadolinite exhibits -with the 

 Mineral Acids. 



The gado'inite (it is by this name I fhall diftinguifh this 

 ftone in the courfe of this memoir,) is attacked by the power- 

 ful mineral acids, fuch as the fulphuric, the nitric, and the 



muriatic; 



