UNCOMMON SPECIES of ZEOLITE. 301 



fome traces of the muriatic acid could be diflinguiflied, al- 

 though the quantity was very fmall. With regard to the pro- 

 portion of the earths, the refults of the fecond analyfis corre- 

 fponded almoft; ex^dtly with the former. 



I ALSO expofed fome of the' zeolite to the adlion of the ful- 

 phuric acid, in the following manner, with the view of obtain- 

 ing the foda only, the earths being difregarded. One hundred 

 grains *, reduced to fine powder in the flint mortar, were mixed 

 with 250 grains of fulphuric acid, diluted with twice its weight 

 of water. Some heat and very flight efFervefcence were produced, 

 and the mixture foon became thick and gelatinous. It was 

 then evaporated flowly to drynefs in a fand-bath, in a cup of 

 Chinefe porcelain ; and the dry mafs was pulverized and boiled 

 for half an hour with water, and filtered. Having waflied the 

 vmdiflblved refiduum fufficiently, I boiled the filtered folution 

 with carbonate of ammonia, which precipitated fome earthy 

 matter. After this had been feparated by filtration, the folu- 

 tion was evaporated to drynefs by a gentle heat ; and the faline 

 mafs left was put into a crucible, and heated flowly to rednefs. 

 A white fait remained in the crucible, which weighed 19 grains. 

 To free this fait from any remains of earthy falts which might 

 be mixed with it, I diflTolved it in a fmall quantity of water, 

 added fome carbonate of ammonia, and boiled the mixture for 

 a few minutes, by which means a flight earthy precipitate was 

 thrown down. This being feparated as before, the fait was 

 again colledled by evaporation, and heated to rednefs. It now 



Vol. v.— p. II. Q^q weighed 



* I HADE ufe of fmall quantities only of the zeolite in all thefe experiments; 

 becaufe, as the fpecimen appears to be the only one of the kind which has beea 

 found, I wiftied to preferve as much of it entire as poffible. 



