ANALYSIS OF THE NATROLITE. 193 



/. The alcaline folution e was mingled with muriatic acid, Alumine fepa- 

 till the precipitate produced, became rediflblved, and was then a^ne folutW 

 decompofed by carbonate of foda. The precipitate obtained 

 after being waflied, dried, and ignited, weighed 24^ grains. 

 It was alumine. 



g. It remained ftill to examine the alcaline part of the foffil. The alcaline 

 which produced with muriatic acid the 31| gr. c. and the^^Jj^ e o # 

 two grains d. Tafte, figure of cryftals, and chemical re- 

 agents, proved it to be muriate of foda. A folution of it in 

 water, mingled with a concentrated folution of tartareous 

 acid, did not produce tartarite of potafli. Another part of 

 the folution, after being decompofed by fulphuric acid, yielded 

 fulphate of foda. -i 



Having afcertained by experiments that 100 parts of abfo- 

 lulely pure carbonate of foda *, dried in a heat of ignition, 

 when faturated with muriatic acid, loll 4 1 parts by weight of 

 carbonic acid, and yielded 120J- parts of dry muriate of 

 foda ((he deficcation of which was not continued to decre- 

 pitation) we may conclude, that the above 331 grains of mu- 

 riate of foda contained 16| of foda. 



100 parts of the natrolite confequently yielded ; Component 



parts of natrC" 

 lite. 



Siliceous earth B. 



a 



- 



- 43. grs 



Alumine 



f 



- 



- 24.25 



Oxide of iron - 



€ 



- 



- 1.75 



Soda 



g 



- 



- 16.50 



Water - A. 



a 



- 



9.— 



99.50 



The fmall number of foffils which contain foda, is therefore 

 augmented by one more. That foda was contained in this 

 ftone might perhaps have been expeded, on account of its 

 forming frequently the matrix of the fonorous porphyry, which, 



* In order to obtain perfeftly pure carbonate of fods, I diflblve Pu« carbonate 

 common carbonate of foda in water, and faturate this folution ° ° *• 

 with nitric acid, taking care that the acid is a little in excels. I 

 then feparate the fulphuric acid by nitrate of barytes, a<id the 

 muriatic acid by nitrate of filver. The fluid thus purified I eva- 

 porate to drynefs, and fufe the nitrate of foda obtained, and decom- 

 pofe it by detonation with charcoal. I then elixiviate the refidue, 

 filter, and cryflalize the carbonate of foda. 



Vol. VI.— November, 1803. O it 



