lane tert nm 
On the Discovery of Fluoric Acid in the Condrodite. 359 
to the Mineralogical Journal of Dr. Bruce,} to Professor 
Cleaveland’s works,{ and the late illustrious "Haiiy. § The 
last named philosopher has told us, that he received some 
specimens of this mineral from Doctor Bruce, with the in- 
formation that it wasa Silico Calcareous Oxide of Titanium, 
and that he, relying upon the Doctor’s account of it, adopt- 
ed the error, until it was removed by his ‘own crystallo- 
graphical investigation, and by Berzelius’ account of the 
analysis which he made of it; he then considered it a Sili- 
cate of Magnesva,|| substituting one error for another. Such 
was the state of their knowledge, on the continent of Eu- 
rope, concerning the composition. of this mineral, at the 
close of 1821, and in Gteat-Britets,* eet had made no fur- 
ther progress concerning it in 1822.* 
Notwithstanding the facts above referred to, Mr. Nuttall, 
in his reply, relates that Dr. Langstaff, of New-York, as 
long ago as 1811, analyzed the Sparta mineral, and he then 
gives the doctor’s account ~ it as follows, viz. “it yielded 
about, : 
Silex ‘ - 
32 
Oxide ofIron - 6 
sc - 51 
Wa - - 2 and by abstraction, 
Fluorie Acid 9 
100 
The reader wil estimate the value and necessi “0 the - 
word “gbout” in the foregoing statement, when the num- 
bers given ebnabet us to so exact a result! Dr. Langstaff 
was'a pupil in Dr. Bruce’s Laboratory, and it is now as- 
serted, that the above analysis was made there in 1811. 
Is it probable, if such had been the fact, that Dr. Bruce 
would have remained, until his decease, ignorant of it? or 
that, if he had known it, he would, several years thereaf- 
+Bruce’s American Mineralogical Journal, Vol. I. 239. 
tCleaveland’s Mineralogy, p. 158, first edition, 1818. 
§Annales des Mines, Vol. VI. p. 527. : 
\[lbid. 
*Journal of the Royal Iustitution of G. B. Vol. XII. p. 329. 
