CHEMICAL SCIENCE. 195 



7. The spectroscope detects in the dried salts neither lithium, 

 calcium, nor rubidium. They contain but little sulphuric acid; 

 but are composed almost exclusively of chloride of magnesium, 

 sodium, calcium, and potassium, and of a certain quantity of the 

 bromides of these bases. Their relative richness in bromine and 

 potassa is such as to deserve the attention of manufacturers of 

 these articles. 



8. The waters of the rivers and si3rings around the Dead Sea 

 are composed of chlorides, sulphates, and carbonates of lime, 

 magnesia, soda, and potassa, and contain no bromine appreciable 

 to analysis. 



Water of the Bed Sea. — MM. Robinet and Lefort have just 

 submitted to the Academy of Sciences of Paris an analysis of the 

 water of the Red Sea. It shows that in a litre there are 45.38 

 grammes of fixed salts, of which 30.30 are chloride of sodium, 

 2.88 chloride of potassium, 4.04 chloride of magnesium, .06435 

 bromide of sodium, 1.79 sulphate of calcium, and 2.74 sulphate" of 

 magnesium. Except in being a little more intensely saline, the 

 composition of the water of the Red Sea is thus just the same 

 as that of average sea-water, but very different indeed from that 

 of the Dead Sea, so that this analysis quite disproves the hypoth- 

 esis that between the Dead Sea and the Red Sea there exists a 

 sul)terraneous communication. 



The following tal)le, by MM. Roljinet and Lefort, from the 

 •' Comptes Rendus," gives the percentage composition of the res- 

 idue obtained by evaporation from the waters of the Mediterra- 

 nean, Red Sea, and Dead Sea: — 



Mediterranean. Red Sea. Dead Sea. 



Chlorine 52.92 60.33 65.78 



Bromine 1.14 1.11 1.25 



Sodium 31.15 30.92 11.22 



Potassium 7.00 3.33 3.71 



Calcium 1.18 1.16 5.67 



jMagnesium .' 3.G2 3.54 12.59 



Sulphuric Acid 6.42 €.35 1.05 



From this we perceive that while the Mediterranean has a much 

 larger quantity of potassium than either of the others, and both it 

 and the Red iSea have nearly three times as much sodium as the 

 Dead Sea, the latter has more chlorine, nioi'e calcium, more mag- 

 nesium, and less sulphuric acid than either of the former. 



AN ADVANTAGEOUS METHOD OF PREPARING OXYGEN. 



Fleitmann's method of preparing oxygen from bleaching-pow- 

 der depends on the coniph^te decomposition of a concentrated 

 solution of hypochlorite of lime, when warmed, with a trace of 

 freshly-prepared moist hyperoxide of cobalt, into oxygen and a 

 solution of chloride of calcium; no chlorate of lime is foi*med, 

 and the whole of tlie active oxygen is given off, at a temperature 

 of 70° to 80° C, in a regular current, with a gentle foaming of 

 the liquid. His explanation of the process is that a lower hyper- 



