172 Intelligence and Miscellanies 
was announced by Professor Cleaveland in his first edition 
of Elements of Mineralogy under the name of Brucite as a 
luate of magnesia without noticing the presence of silex 
so distinctly obtained by Doctor Langstaff. Nor can | omit 
the experiments made five years ago ) by my friend Doctor 
Torrey, who also found the existence of Fluoric acid as 
well asthe 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 
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, 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 o 
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 ” 
pears also in corroboration of this opinion.* After all, 
in no way anxious on the subject, and am perfectly willing 
that Mr. Seybert should consider the fluoric acid as essential, 
while ie oe want of better proof, shall still be inclined to 
as accidental. I would hope, that as lovers of 
science ‘and “of truth, these and many other discrepancies of 
on matters of this kind, might harmlessly and 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, . agoake 51 
Water, who $ he ence Band by abstraction 
Fluoricacid, - ee - . 9 
100 
ours truly, Ww. LANGSTAFF.” 
from his Wiinutes made at the time that the Fluori¢ 
Doctor L. assured me 
acid then obtained from the Brucite was. sufficient to engrave and corrode @ 
a plate of glass, 
* Since publishing the account of this mineral, several other localities © of 
it, particularly at Wes a Point i 
I have likewise observed it in several more specimens, with Idocrase and mi- 
rom Vesuvius ; in thes no trace of fluoric acid has as yet been discover~ 
bn ‘it is consequently, very nearly related to olivin, in its chemical composi- 
