EGYPTIAN riELIOTROPlUM. ^'jf 



fother acid employed. It was therefore filtered, and the info- 



luble part colleded. This infoluble refidue was of a fine red tnfolubk (red) 



colour, and hardi to the touch. It weighed 2| grains. But P'^''f " ^°''"'* 



.., with muriatic 



after having been boiled in muriatic acid, it loft | grain, and acid gave a little 

 acquired a perfeft white colour. The acid made ufe of for ''■°"' ^ndleft 

 that purpofe proved to have flripped it of iron to that amount. 

 It was therefore a portion of filex which had eluded the firfl 

 procefs employed for feparating this earth. 



The muriatic folution from which this liliceous earth had The lafl muria- 

 been feparated, I mingled with a folution of carbonate of'^*^ t°d''°b f 

 potafti, till no further turbidnefs enfued. The obtained pre- 

 cipitate was transferred after repeated ablutions in water, into 

 a boiling folution of potath, and digefted in that fluid for 6ne 

 hour. The mixture was then diluted with water, and ihe in- 

 foluble part feparated by the filtre. 



The alcaline folution was faturated with muriatic acid, and The akaline hf 

 decompofed by carbonate of ammonia in excefs ; the precipi- '""®n was de- 

 late obtained by this means, after having acquired a confider- carbonate of am« 

 able confiftence, was digefted in acetous acid, and examined "lon'a? a"d di- 

 for magnefia, but no veftige of fuch earth could be detefled tous acid 

 It was therefore dried and ignited, its weight amounted to 20| and the folutioa 



contained no 

 g""^'"^- _ _ ^ magnefia, but 



The infoluble refidue from which this earth had been fepa- only alumina* 



rated, was again dilTolved in muriatic acid, and into this folu- '^^^ refidue not 

 T 1 1 f - 1 • -11 ii I r 1 1 taken up by the 



tion 1 dropped hquid ammonia till the odour or the latter con- acetous acid was 



fiderably predominated. A brown flocculent precipitate fell again difi^blved 



down, which was collefled, waftied in liquid ammonia, and and^m-edD^bv 



boiled for a few minutes in a folution of potafh. It was then excefs of ammo^ 



transferred into a fmall retort, and nitric acid affufed upon it, "'?*. 



This piecip. 

 which was again diftilled off from it repeatedly. The retort after perfeiS fe- 



was laftly heated to a dull rednefs. The precipitate now P^f^"^'"" °^ ^" 



. , , . acid, and coni- 



weighed 29 grams. ^ plcte oxidation 



The fluid from which this precipitate had been obtained, ^y nitric acid, 

 together with the folution of potafh tiade u/e of for boiling it, '^x]d7onrm. ^^ 

 was then mixed with muriatic acid^ and afterwards decompofed The fluid from 

 by the addition of carbonate of potafh. The produd obtained, J^jf^en^f'"^. 

 eflervefced with muriatic acid, and yielded fulphate of lime on rated was mixed 

 effaying a fmall quantity of it by fiilphuric acid. It was there^ "^^^ d'^coVoftd 

 fore dried, and expofed tea white heat, after which its weight by carb. potafh. 

 was 56f grains. iiwe fell down. 



F 2 The 



