WATERS from ICELAND. 97 



voyage, this matter being one of thofe volatile ingredients of 

 mineral waters, which are the mod liable to be evaporated or 

 changed by the action of the air and other caufes. I therefore 

 think it fufficient to mention, that thefe waters contained a fmall 

 quantity of this fubftance. 



I began by making a few preliminary trials, to acquire fome 

 notion of the nature of thefe waters. 



1. An equal quantity of lime-water being added to the Ice- 

 land waters, there was a little diminution of tranfparency, but 

 only in the final left degree, and no fediment was formed. 



2. Mild volatile alkali produced no effect whatever. 



3. Paper ftained blue with the March violet, being dipped 

 into the water and dried, had its colour changed a little towards 

 a green. 



4. Cambric ftained to a bluifh purple, with infufion of 

 litmus, affumed a more perfect blue colour, when dipped into 

 the water and dried. 



5. Acid of fugar did not produce a perceptible muddinefs or 

 precipitation. 



6. Nor did the folution ^f corrofive fublimate. 



7. The folution of fal faturni (plumbum acetatum) made 

 the water very muddy and white, but a fmall quantity of 

 diftilled vinegar redilTolved nearly the whole of the precipitate, 

 and made the water almoft perfectly clear again. 



8. The folution of barytes in jnuriatic acid made the water 

 become muddy, and depofite a fediment, which was not redif- 

 folved by adding purified nitrical acid. 



9. The folution of filver produced a ftrong muddinefs and 

 confiderable precipitation, which was not rediffolved by adding 

 purified nitrical acid. 



The laft trial fhewed the prefence of the muriatic acid, and 

 the one preceding it, that of the vitriolic acid in the compofition 

 of thefe waters ; but by the 3d, 4th and 7th, I alfo learned, 

 that there was more than enough of alkaline matter to faturate 



Vol. III. N both 



