1826.] Scientific Notices— Chemistry. 145 



tabular calcareous grit occurs, Mr. Murcliison has discovered, 

 together with scattered shells of the Vivipara jiuviorum, the 

 bones of a large unknown vertebrated animal, specimens and 

 drawings of which accompany this memoir. 



Jan. 6, 1826. — The reading of Mr. De la Beche's paper on 

 the Geology of Jamaica, was continued. E. W. B. 



Article XIII. 

 SCIENTIFIC NOTICES. 



Chemistry. 



1. Prof. Berzelius's Discovery of Lithia in Mineral Waters. 



Prof. Berzelius has been occupied with the examination of 

 several mineral waters from Bohemia, viz. those of the Eger, or 

 Frauzensbad, and those of Marienbad. These waters were 

 found to contain the same substances which this chemist 

 detected in those of Carlsbad, the analysis of which has been 

 for some time before the public,* but in the new analysis he has 

 found no lithia. The quantity of the carbonate of the alkali is 

 very small, particularly in the waters of Carlsbad, and in that of 

 Eger ; but the waters of the spring called Kreuzbrunn, at 

 Marienbad, contain as much as a centigramme of the carbonate 

 of lithia in every bottle. 



The following is M. Berzelius's method of discovering this 

 alkali in any solution. He precipitates the lime by means of 

 oxalate of potash, and afterwards separates the magnesia by 

 carbonate of soda ; but the mixture must be evaporated to dry- 

 ness, and the residue fused ; for otherwise some of the magnesia 

 would be easily redissolved in the form of a double carbonate of 

 soda and magnesia. The mass taken up by the water and 

 filtered will not give any further precipitation even when pure 

 phosphate of soda is added; but if it contain lithia it will 

 become turbid during the evaporation, which must be continued 

 till the matter be perfectly dry. It is next redissolved in a very 

 small quantity of cold water, which leaves undissolved a double 

 phosphate of soda and lithia, equivalent to one-third of its 

 weight of carbonate of lithia. The characters which distinguish 

 this phosphate from the earthy phosphates with which it may be 

 confounded, are as follows : It is very fusible before the blow- 

 pipe. When melted with carbonate of soda, it enters with the 

 soda into the charcoal. On a leaf of platinathe melted mixture 

 is limpid. The earthy phosphates remain on the charcoal while 



• Sec Annals of Philosophy, vol. viii. N, S. p. 123. 



Neut Series, vol. xi. i. 



