WATER OP THE DEAD SEA. g^ 



1. 20 grains of this water (the whole supply of which By evapora- 

 amounted only to 540 grairis) were put into a glass capsule, ^^°"' 



and slowly evaporated in a water bath, by means of an ap- 

 propriate apparatus, the temperature of the capsule being 

 constantly kept within 5 degrees of 180*^. The object of 

 this experiment was simply to know the weight of the solid 

 contents of the water, dried under various degrees of heat, 

 and to observe the appearances produced by evaporation. 

 After a few hours, and when the residue had ceased to lose 

 weight, the saline mass, whilst still warm, appeared in the 

 form of a white semitransparent incrustation, which yielded 

 to the touch, being soft, and of a pulpy consistence. In 

 cooling it became hard, and of a much more opaque white 

 colour. When examined with attention, the borders of this 

 mass were found covered with small cubic crystals, and the 

 same appearance was observed, though less conspicuously, 

 in the centre under the saline incrustation, when in the state 

 of semifusion just described. On standing in the air for 

 some time, the white opaque mass gradually absorbed water 

 from the atmosphere, and returned to a liquid state. The 

 20 grains of the water, thus evaporated and dried at 18C, 

 weighed, whilst still warm, 8'2 grains. 



2. The same saline mass, being afterward exposed in a 

 sand bath to the temperature of 212° Fahrenheit, was re- 

 duced to 7*7 grains. Hitherto not the least smell of muria- 

 tic acid was perceived, nor did any decomposition appear to 

 take place. 



3. But having raised the heat about 15° higher, the resi- 

 due, after a few miimtes, was found reduced to 7*4 grains; 

 and on redissolving it, a few insoluble white particles appeared 

 floating in the solution, showing an incipient (decomposition 

 in the muriate of magnesia. 



It appears from these experiments, that 100 parts of the 

 Dead Sea water yield 41 of salts dried at 180°, and 38*5 

 dried at 212°*. What proportion these quantities bear to 



the ' 



* If the quantity of materials upon which these results are founded 

 should appear too small, I would observe, that, if the bulk of salt be • 

 considerable, it is impossible to dry it accurately, owing to the crust 

 which forme on the surface, and prevents the escitpe of moisture. But 



Vol . XX — May. iSOd, D a? 



