X74 ANALYSIS OF SULPHATE OF BARYTES. 



III. 



On the Analysis of Sulphate of Barytes. By Mr. Jameu 

 Thomson. Communicated by the Author. 



Sulphate of X HE analysis of sulphate of barytes has engaged the at- 

 accuTnt«*!y as- tent ion °f many distinguished chemists ; yet the problem, 

 ccrtaintd. though of easy solution, may be considered as still unre- 

 solved, since the greateft discordance prevails in their re- 

 sults. The accurate determination of the relative propor- 

 tions of its constituents, as far as concerns its chemical or 

 mineralogical history, is a matter of secondary considera- 

 This an im- tion ; but the soluble combinations of barytes being them- 

 portant object, se j ves } m p 0r tant inftruments of analysis, m detecting the 

 presence and ascertaining the quantities of sulphuric acid in 

 any compound by the production of sulphate of barytes; 

 the analysis of sulphate of barytes itself becomes an object 

 of considerable importance, and involves in it the accuracy 

 of the analysis of alrnoft all compounds, into which sulphur 

 or sulphuric acid enters. - 



Its cwnposi- Withering, Black, and Klaproth, who have examined 

 ticn according g^p composition of this salt, agree with Kirwan in stating 

 it as composed of sulphuric acid 33, barytes 67. 



According to Fourcroy it is composed of acid 34, bary- 

 tes 66. 



According to Thenard of acid 25*18, barytes 74*82. 

 According to Berthollet of acid 27, barytes 73. 

 And according to the experiments of Chenevix, of acid 

 23 '5, barytes 76*5. 



Clement and Desormes, in consequence of the discord- 

 ance of these results, eugaged in a series of experiments, 

 which appear to have been conducted with great care ; and 

 from which they conclude, that sulphate of barytes is com- 

 posed of acid 32*18, barytes 67*82. 



And Klaproth once more revised and confirmed his for- 

 mer analysis, which gave 33 acid and 67 barytes, as the 

 composition of this salt. 



The labours of these distinguished chemifts, together 

 with the general accordance of their results with those ob- 

 tained 



