3 T4 Chemical Analji/ts of 



poration a white fait remained, which was heated gradually 

 in a crucible to volatilize the muriate of ammonia formed in 

 the courfe of the analyfis. When while vapours ceafcd to 

 rife, the heat was increafed to rednefs, and a fait was lett 

 which weighed 17 grains. On rcdi'Jolving it in a fmall quan- 

 tity of water, and boiling the folution with carbonate of am- 

 monia, a minute portion of carbonate of lime was precipi- 

 tated, which weighed one grain; equal to about half a grain 

 of pure lime. I obtained the fall by a fecond evaporation ; 

 and after it had been expofed again to a very low red heat, it 

 weighed 16 grains, and confiQed wholly of muriate of ibda. 



According to Mr. Kirwan's experiments, 16 parts of mu- 

 riate of foda in crvftals contain 8*5 parts of foda; but the 16 

 parts above mentioned, by having been dried in a red heat, 

 and confequently freed from water of cryllallization, would 

 contain fomewhat more than 8*5 parts of foda. However, 

 the proportion of foda in iod parts of the zeolite may be 

 ftated at 8*5 parts, which, though probably rather lefs than 

 the real quantity, muft be very nearly correct. 



Having finifhed the experiments juft defcribed, I analyfed 

 the zeolite a fecond time ; and inade ufe of nitric acid, for 

 the purpofe of afcertaining whether any muriatic acid en- 

 tered into its compofition. By the teft of nitrate of filver, I 

 found that fome traces of the muriatic acid could be diftin- 

 guithed, although the quantity was very Imall. With regard 

 to the proportion of the earths, the refults of the fecond 

 analyfis correfponded almoft exa6lly with the former. 



I alfo expofed fome of the xeolite to the aftion of the ful- 

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

 taining the foda only, the earths being difregarded. One 

 hundred grains *, reduced to fine powder in the flint mortar, 

 ■ift-ere mixed with 250 grains of fulphuric acid, diluted with 

 twice its weight of water. Some heat and very flight efler- 

 vefcence were produced, and the mixture foon became thick 

 and gelatinous. It was then evaporated llowly to drynels in 

 a fand-balh 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 undiflblvcd refuiuum fufikiently, 

 I boiled the filtered folution with carbon.ite of ammonia, 

 which precipitated fome earthy matter. After this had been 

 feparatcd by filtration, the folution was evaporated to drynefs 



• I made ufc of fmall quantities onlv of the zeolite in all thcO cxpcri- 

 n'.cnts; becaufc, as the fpccimen appears to be the on'y one of i!ic kind 

 ^vh'ch lias been found, I wiihed to prcferve as much ot it entire as pol- 

 fible. 



by 



