WATERS from ICELAND. ioi 



ftrongly directed, the mixture was foon melted into a tranfpa- 

 rent colourlefs glafs, which afterwards, by being digefted with 

 a fmall quantity of diftilled water, was completely diflolved, 

 and formed a liquor which had all the qualities of the liquor fi- 

 licum. 



I need not take notice here of the quantity of the earth 

 and faline matter which were in fome meafure feparated 

 from one another in this experiment. I had reafon to fufpecl, 

 that neither of them were obtained in this way without fome 

 lofs. The odour emitted by the water in the end of evapora- 

 tion, gave reafon to fufpect the lofs of fome part of the falts ; 

 and it was probable that a part of the earth would remain com- 

 bined with the alkali, in a foluble ftate, in the dry extract, and 

 would pafs through the nitre, when 1 diflolved and warned away 

 the faline matter. 



I therefore planned a fet of experiments, by which the 

 quantity of each ingredient in thefe waters might be more cer- 

 tainly known ; and began with the following 



Experiments to investigate the quantity of the un-neiitralized alkaline 

 fait. 



In making the experiments to decide this queftion, I made 

 life of an acid, which I had often employed before in experi- 

 ments to learn the quantity of pure or cauftic alkali, contained 

 in aerated alkalis, and in various barillas, kelps, and other fuch 

 heterogeneous maffes. This acid was a quantity of the vitriolic, 

 the power of which, in faturating pure alkalis, I had carefully 

 examined, and I was accuftomed to add it very gradually to fil- 

 trated folutions of the above fubftances, until they were exactly 

 faturated ; and then, from the quantity of acid required to pro- 

 duce this effect, I learned the quantity of un neutralized alkali 

 which thefe fubftances contained. The fpecific gravity of this 



vitriolic 



