1813J of the Water of ike Bead Sea. 133 



me indispensable data, whatever mode of proceeding I might 

 wish to adopt. I then tried various methods upon artificial 

 solutions resembling the Dead Sea, the contents of which being 

 previously known to me, I was enabled to ascertain, and com- 

 pare with precision, the degree of confidence which these 

 methods deserved. Having, at last, found one of them which 

 yielded very accurate results, I proceeded to apply it to the 

 water of the Dead Sea. 



This method simply consisted in precipitating the two earths,^ 

 magnesia and lime, by appropriate re-agents, and calculating 

 from the precipitates obtained, the quantity of muriates to 

 which these earths respectively belonged. The muriate of soda 

 was first only inferred, from the quantity of muriatic acid found 

 in the water ; but, in another instance, it was actually obtained, 

 after the separation of the earths, in the form of crystals; and 

 the degree of coincidence in the results was such as can scarcely 

 be exceeded in chemical analysis. 



The state in which the weiglit of these salts was estimated, in 

 summing up the contents of the Dead Sea, was that of a perfect 

 desiccation, such as can only be obtained by a red heat ; and in 

 the case of the muriate of magnesia (which cannot be actually 

 heated to redness without undergoing decomposition), the neces- 

 sary allowance for moisture was easily and accurately inferred 

 from the known composition of this salt. 



The method used by Mr. Klaproth (which for the sake of 

 comparison, it is necessary that I should here also state in a few 

 words), consisted in treating tlie residuum of the Dead Sea 

 water, evaporated in a sand-bath, with alcohol, in order to 

 separate the two earthy salts^ which are soluble in this men- 

 struum, from the muriate of soda, which is but sparingly 

 dissolved by alcohoLf He then redissolved the earthy salts in 



Davy, Berzelius, Gay-lussac, aud, in general, by those chemists who have 

 turned their attention to the exact propoi liosns in which bodies combine. 



* The solid contents of the Dead Sea consist of muriate of magnesia, muriate 

 of lime, and muriate of soda, w ith a vestige of sulphate of lime. 



t That alcohol is capable of dissolving a certain proportion of muriate of 

 soda (especially when there are deliquescent salts present which contain a great 

 deal of water), Mr. K. seems to have been perfectly aware ; for he treated the 

 mass a second time with a smaller quantity of alcohol, in order to remove that 

 source of error. As, however, he does not mention either the specific gravity, 

 or the proportion of alcohol used in this second operation, it is natural to 

 suppose that the same error v/ould again occur, in some degree, m the second 

 process. Having thought it worth while, in company with two friends, to try 

 a direct experiment on the subject, about 100 grains of pure alcchol, of the 

 specific gravity of 814, were mixed and agitated with a mixture of 5 grs. of 

 muriate of soda, and 10 grs. of muriate of lime, in crystals. The residue left 

 andissolved by the alcohol weighed only 4*5 grs.; and yet this residue was 

 found to contain a notable quantity of lime ; showing that the alcohol had dis» 

 solved some of the muriate of soda, without having taken up the whole of the 

 muriate of lime; a circumstance which must, of coursCj have materiailij* 

 affected the results obtained by Mr, Klaf)roth'fe meUiod, 



