1881.] 



475 



[Konig. 



Deducting tlie insoluble (barite) we obtain per cent. 



Notwithstanding the simple ratio, this result cannot be utilized to base 

 definite conclusions thereon, since there is an unaccounted loss of nearly 

 5 per cent, in the analyses. From the same specimen material was now 

 taken off another corner, and 2 analj^ses made as follows : 



C (1^.000) D (1^.0000) Mean. 



PEOC. AMER. PHILOS. SOC. XIX. 109. 3h. pkixted jtly 25, 1881. 



