128 Prof. Berzelius on Lithia in Mineral Waters. 



Art. XXV. — Account of the Discoveries and Experiments of 

 the Swedish Chemists during 1 the year 1825. Drawn up for 

 this Journal by a Correspondent at Stockholm. 



1. Professor Berzelius''s Discovert/ of Lithia in Mineral 



Waters. 



Professor Berzelius has been occupied with the examina- 

 tion of several mineral waters from Bohemia, viz. those of 

 the Eger, or Franzensbad, 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 also lithia. The quantity of the carbo- 

 nate of the alkali is very small, particularly in the waters of 

 Carlsbad, arid in that of Eger ; but the waters of the spring 

 called Kreuzbrunn, at Marienbad, contain as much as a cen- 

 tigramme 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 magne- 

 sia by carbonate of soda, but the mixture must be evaporated 

 to dryness, 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 farther precipitation even 

 when pure phosphate of soda is added ; but if it contains lithia, 

 it will become turbid during the evaporation, which must be 

 continued till the matter be perfectly dry. It is next redis- 

 solved 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 charac- 

 ters which distinguish this phosphate from the earthy phos- 

 phates 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 platina the melted mixture is limpid. The 



" See this Journal, vol. ii. p. 176, January 1825. 



