1824.] On the Mineral Waters of Carlsbad. 123 



gas is at first evolved, in consequence of siliciuvet of potassium 

 having been formed, which cannot exist in water. The washed 

 substance is a hydruret of silicium, which, at a red heat, burns 

 vividly in oxygen gas, although the silicium is not thereby com- 

 pletely oxidated ; it is then heated in a covered platina crucible, 

 the heat being slowly raised to redness. The hydrogen alone is 

 oxidated, and the silicium is now no longer combustible in oxy- 

 gen ; but chlorine attacks it readily. The small portion of silica 

 that is formed may be dissolved by fluoric acid. If silicium has not 

 been exposed to a strong red heat, the acid dissolves it, with a 

 slow disengagement of hydrogen. According to my synthetical 

 experiments, silica contains 0'52 of its weight of oxygen. Zir- 

 conium is obtained by an analogous process. It is as black as 

 charcoal, is not oxidated either by water or muriatic acid, but 

 aqua regia and fluoric acid dissolve it ; the latter with disen- 

 gagement of hydrogen. It burns with extreme intensity at a 

 slightly elevated temperature. It combines with sulphur. Its 

 sulphuret is chesnut-brown like silicium, insoluble in muriatic 

 acid and the alkalies. It burns brilliantly, and the products are 

 sulphurous acid gas and zirconia. 



Article XIII. 



On the Mineral Waters of Carlsbad. By Jac. Berzelius* 



Carlsbad is situated in a deep and very narrow valley, not 

 far from the place where the latter terminates in the valley of 

 the river Eger. Through the middle of this spot, there flows 

 the little river Tepel, on both of whose banks, and within a short 

 distance from one another, the hot springs first issue from the 

 earth. The springs themselves are extremely numerous, but 

 those resorted to by the strangers at Carlsbad are only the fol- 

 lowing : the Sprudel, the Hvgeian spring, the Mill spring 

 (Muhlbrunn), the New spring (Neubrunn), the Empress There- 

 sa's spring (Theresienbrunn), St. Bernard's spring (Bernhards- 

 Ijrunn), and, but much seldomer than the others, the Hospital 

 spring (Spitalsbrunn). All of them issue from a species of 

 limestone, and into each of the outlets there has been inserted an 

 artificial pipe, through which the water, impelled by the internal 

 pressure, is thrown up into the air in an uninterrupted jet, in a 

 manner very convenient for those who drink it. This limestone 

 is formed by the water itself; for the latter, in proportion as it 

 loses carbonic acid, is incessantly depositing a concretion of a 

 compact and crystalline texture, on every substance with which 

 it comes in contact. 



* Abridged from the Kongl. Vet. Acad. Hiindl. 1822, p. 139. 



