Page:Proceedings of the Royal Society of London Vol 1.djvu/297

This page needs to be proofread.
277


tity of acid in luna cornea having been previously determined to be 1905 per cent, by means of the weight of luna cornea, produced by a given quantity of acid.

The method found most successful for analysing the artificial com- pound solution, consisted in dividing it into two portions, from one of which the acidwas precipitated by nitrate of silver, and its weight ascertained. From the other the lime was precipitated by oxalate of ammonia, and the magnesia by caustic potash. The respective quan- tities of acid, combined with each, being thence deduced by assistance of the preceding experiments, the quantity of muriate of soda could be inferred from the remaining quantity of acid.

By this method a compound solution known to contain

8'17 muriate of lime ed b t .31 8.14 2610 muriate of magnesia appear ty. n 25-62 25 muriate of soda to am am 25'47

After this series of preliminary experiments, Dr. Marcet proceeded to the analysis of the water itself, of which 100 parts by evaporation, at a temperature of 180°, left a residuum of 41, and at 212°, 38%.

When 100 grains of the water Were treated by muriate of barytes, they gave a precipitate of one-tenth of a grain of sulphate of barytes.

Another portion, weighing 250 grains, by addition of nitrate of silver yielded a precipitate of 163'2, a quantity equivalent to 31'09 acid. Oxalate of ammonia being then added, occasioned a precipitate containing 4'814 pure lime; and hence the quantity of muriate of lime is computed to be 9'48.

The clear solution, containing the nitrates of magnesia and of soda, with oxalate of ammonia, having then been concentrated by evapo- ration, subcarbonate of ammonia occasioned a precipitate containing “‘1 of _ pure magnesia, which are equivalent to 25'25 muriate of magnesia.

After deducting the quantifies of acid contained in these muriates from the quantity estimated by luna cornea, there remained 12'28 for acid in the muriate of soda, which, by estimation from preceding experiments, was thus found to be 261353.

These results being brought into one view, the water of the Dead Sea appears to contain, in every 100 parts,

Muriate of lime . . . . . . . . . . . . . . . . . . . . . . . . 3'792 Muriate of magnesia . . . . . . . . . . . . . . . . . . . . 10'100 Muriate of soda . . . . . . . . . . . . . . . . . . . . . . . - 10‘675 Sulphate of lime . . . . . . . . . . . . . . . . . . . . . . 0'054

241332

being the total amount of saline matter when perfectly dry.

The same chemical reagents as were used to discover the general properties of the water of the Dead Sea being applied to that of the river Jordan, were found to produce analogous effects. But the quantity of saline matter was so small, that on evaporation of 500 grains at about 200°, the residuum weighed only eight tenths of a grain.