IV. A Chemical Analysis of Three Species of Whin- 

 stone, and Two of Law a. By ROBERT Kenxedt, M. D. 

 F. R. S. & F. A. S. Edin. 



[Read, December 3. 1798.] 



ON the 5th of Augufl laft, I announced to the Society that 

 I had difcovered foda in feveral varieties of the whin- 

 Hone * of Scotland, and alfo in lava from Mount ^tna ; but did 

 not defcribe the various experiments to which thefe fubftances 

 had been fubjecfled in my examination of them. In the follow- 

 ing paper, therefore, I have the honour of laying an account of 

 thefe experiments before the Society. 



ANALYSIS I. 



Bafalt of Staffa. 



The fpecimen of this bafalt, fubmitted to the following ana- 

 lyfis, was given me by a gentleman, who brought it himfelf 

 from the celebrated bafaltic columns in Staffa. A defcription 

 of its external mineralogical charadlers may be found in Sir 

 James Hall's paper, (p. $$, of this volume), to which I beg 



leave to refer. 



This 



* The name whinftone is nfed throughout this paper in a generic fenfe, compre- 

 hending bafak, trap, certain kinds of porphyry, wacken, and fome other ftones of 

 the argillaceous clafs. 



