ANALYSIS OF LITIIOMARGE. 17$ 



(luces no froth ; but it is exceedingly detergent* 



Being pulverifed, and boiled for half an hour 

 in dillillcd water, ir will pafs through a filtre of 

 fevcral folds, ilill turbid, with many fubtle par- 

 ticles floating in it, that diminifh its tranfparcn- 

 cv. If to this water a few drops of the fulution 

 of muriated terra ponderofa be added, no pre- 

 cipitation is obferved ; from which it may be in- 

 ferred to contain neither vitriolic acid, gypfum, 

 or i:ny fait combined with that acid. But if 

 the nitrous folution of filvcr be poured into it, a 

 milky fedimcnt foon makes its appearance, which, 

 on being expoied to the rays of the fun, immedi- 

 ately becomes black; an undoubted proof of the 

 prcfence of the muriatic acid. 



If fubjedcd, in its pulverifed flate, to a fire 

 gradually raifed to a white hcat.it becomes black 

 juft before ignition, but afterwards refumes its 

 natural appearance as the fire increafes. While 

 in this fituation, it emits aqueous vapours, a lit- 

 tle acid. On being cooled, it is found to be 

 15 J Ib. in the centenary lighter than before. 



A final! bit expofcd to the flame. of the blow- 

 pipe, on a piece of coal, decrepitates, but not in 

 fo great a degree a^ the Ofmundic cartli ; it 

 turns black, and melts with ebullition into a 

 dark coloured fpongy inafs. With borax, mi- 

 crocofmic fait, and mineral alkali, it exhibits the 

 fame character as the Lemnian earth. 



Its analyiis was obtained in the fame way as 



thai 



