310 Heinrich Rose. 
which may even amount to five per cent; a fact afterwards 
brought forward by Scheerer in support of his theory of poly- 
v. Bonsdorff were performed in my laboratory ; not under @ 
_€xamined. ‘T’he presence of fluorine as a constituent of mic@ 
had been overlooked by both Klaproth and Vauquelin; it was 
aS found by Rose by heating the mineral in a porcelain retort, with 
object of discovering the source of its loss of weight on ign 
uo-silicic acid came over into the receiver. eee, 
