1835.] Native Sulphate of Alumina and Iron, 69 



Alumina 11*602 



Ammonia 3*721 



Magnesia 0*115 



Sulphuric acid .... 36*065 



Water 48*390 



99*893* 



The stalactitical bitter salt of Neusohl, in Bohemia, 

 contains 



Magnesia 15*314 



Oxide of cobalt ' . . . 0*688 



Oxide of copper . . . 0*382 



Protoxide of manganese 0*343 



Protoxide of iron . . . 0*092 



Sulphuric acid . . . . 31*372 



Water 51*700 



99*891 1 



5. The substances which have been already described are 

 all derived from foreign localities. I now proceed to relate 

 the facts which have been ascertained with respect to the 

 hair salts of this country. 



Mr. Phillips subjected to examination the salt which 

 proceeds from the decomposition of iron pyrites in the shale 

 of the deserted coal mines of Campsie and Hurlet, in the 

 neighbourhood of Glasgow. He obtained 



Sulphuric acid . . 30*9 - 3*07 atoms. 



Protoxide of iron . . 20*7 - 2*3 



Alumina . . . . 5*2 - 1*15 



Water ..... 43*2 - 19*2 



»j 



>» 



100*0 

 The formula deduced from his analysis is 

 2/S. + A1.2 S.'+ 16f Aq.J 

 He repeated the analysis, and obtained the sulphuric 

 acid in excess. 



The conclusions at which I have arrived, after making 

 several careful analyses, are, that the substance is by no 



♦ PoggendorfF, Ann. xxxi. 142. t Ibid. 



% Annals of Philosophy, Second Series, v. 446. 



