173 Intelligence and Miscellanies 



was announced by Professor Cleaveland in his first edition 

 of Elements of Mineralogy under the name of Brucite as a 

 Fluate of magnesia without noticing the presence of silex 

 so distinctly obtained by Doctor LangstafF. Nor can 1 omit 

 the experiments made five years ago by my friend Doctor 

 Torrey, who also found the existence of Fluoric acid as 

 well as the other ingredients mentioned in the analysis of 

 Doctor LangstafF, in the Brucite ; but omitted their publi- 

 cation in deference to the prior labors of Doctor L. from 

 whom he expected an analysis. 



My assertion that this acid (the fluoric) may be accidental 

 rather than essential in the composition of the Brucite, is 

 grounded, I hope with some reason, on its absence in the 

 analysis made by a chemist so celebrated and so accurate 

 as Berzelius. The contiguity of slender veins of fluate of 

 lime to the masses of Chondrodite or Brucite near to Frank- 

 lin furnace at Sparta was also an additional inducement to 

 consider this acid as accidental. Its variable proportion ap- 

 pears also in corroboration of this opinion.* After all, I am 

 in no way anxious on the subject, and am perfectly willing 

 that Mr. Seybert should consider the fluoric acid as essential, 

 while I, for want of better proof, shall still be inclined to 

 consider it as accidental. I would hope, that as lovers of 

 science and of truth, these and many other discrepancies of 

 opinion on matters of this kind, might harmlessly arid even 

 honorably be entertained, without any necessary reference to 

 the opinion of the public, who may be inclined rather to rid- 

 icule us for contention, than credit us for any claim to merit. 



Magnesia, - - 51 



Water, ------ 2 and bj' abstraction 



"Huoricacid, - - - - - 9 



100 



Yours truly, W. LANGSTAFF." 



Doctor L. assured me from his minutes made at the time that the Fluoric 

 acid then obtained from the Brucite was sufficient to engrave and corrode a 

 a plate of glass. 



* Since publishing the account of this mineral, several other localities of 

 it. particularly at West Point in the state of New- York, have been discovsred. 

 1 have likewise observed it in several more specimens, with Idocrase and mi- 

 ca from Vesuvius ; in these no trace of fluoric acid has as yet been discover- 

 ed, it is consequently, very nearly related to olivin, in its chemical composi- 

 tion. 



