On the Discovery of Fluoric Acid in the Condrodite. 359 



to the Mineralogical Journal of Dr. Bruce,! to Professor 

 Cleaveland's works,J and the late illustrious Hauy.§ The 

 last named philosopher has told us, that he received some 

 specimens of this mineral from Doctor Bruce, with the in- 

 formation that it was a 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 Magnesia,\\ 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 Great-Britain, they 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 of it as follows, viz. "it yielded 

 about, 



Silex - - 32 



Oxide of Iron - 6 



Magnesia - 51 



Water - - 2 and by abstraction. 



Fluoric Acid - 9 



100 



The reader will estimate the value and necessity of the 

 word "afeoMi" in the foregoing statement, when the num- 

 bers given conduct 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 therein 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- 



tBruce's American Mineralogical Journal, Vol. I. 239. 



ifCleav eland's Mineralogy, p. 158,^ri< edition, 1818. 



{Annates des Mines, Vol. VI. p. 527. 



yibid. 



♦Journal of the Royal Institution of G. B. Vol. XII. p. 339. 



