i 7 6 ANALYSIS OF LITIIOMARGE. 



that of the two former earths ; and, in a cente- 

 nary of it was found 51.8 of a filiceous powder, 

 tinged yellow with iron ; 3.3 of calcareous earth; 

 0.7 of magncfia ; 25 of argillaceous earth ; 3.7 

 of calcined iron, and 15! of moift volatile mat- 

 ter. 



An excefs of one pound only we attributed 

 to the argillaceous earth. 



By a volatile matter is undcrftood here, as 

 well as in the preceding experiments, not only 

 the dcftrucYton of an oily Jubilance, but alfo the 

 expuUiori of the muriatic acid from its bale, by 

 means of the vitriolic. What this bafe may be 

 is not eafy to determine with fuch fmall quanti- 

 ties; but certainly traces of fea fait appear, how- 

 ever faint, in fomc of the varieties examined by 

 boiling in water, and filtration. We difcovered 

 no fal ammoniac. Perhaps, indeed, it would be 

 neccflary to employ larger malles of earth to 

 procure a more perfect fublimation than has 

 been yet attained. 



v. Corollary. 



FROM a comparifon of the foregoing defcrip- 

 ttons and anulylis the following concluiions may 

 be drawn : 



That, as to the external cbaraftcr, the varie- 

 ties examined are fo perfectly fimilar, that they 

 differ in degree only. The greatcfl difparjty ob- 

 vious 



