224 Discovery of Columbite in Chesterfield, Mass. 
s not my object to determine the proportions among 
the boinnichedts of the present mineral, and I am therefore 
unable to make any precise statement upon the ma Ga > but 
having paid some attention to the relative bulks of the pre- 
cipitates in one or two instances, I was led to conjecture, that 
the columbic acid does not form léss than two thirds of 
the mineral, and that the “it is presént in a proportion, 
little inferior, either to the iron or the manganese ; while t 
lime exists only as a trace. 
B oncluding this account, I would remark, that I am 
not without hope, that a further supply of this desirable min- 
eral, may be found in Chesterfield } although all search which 
has been made, since the discovery of my apenas, has 
oes ineffectual. The fact, that the loose mass which af- 
orded them, was situated, at a little distance from the 
south end of the tourmaline led and that it corres- 
ponded so very remarkably in its = etn structure with that 
part of the rock, seems to indicate that this was its original 
deposit ; and. holds out, I think, sufficient inducement to the 
collector te seoreh for it, in this direction. 
t lso appear worthy of notice, as it seems to indi- 
cate that colamote | is probably a mote widely diffused sub- 
stance, nhgtd has been supposed, Sagic = possess minute masses 
of it from two places in Goshen e, from the farm of Mr, 
Weeks: eotlbe other, four miles itant, from the first discov- 
ered locality of spodumene. In both of these instances, they 
are engaged in the spodumene, in the form of imperfectly 
tabular ctystals. I have also noticed the same substance, in 
very distinct, though minute crystals in Middletown; (Conn.) 
upon on Sok, the high granite hills, about half a mile north 
east of the tourmaline deposit. It occurred in a loose frag- 
man of Granite, consisting chiefly of beryl. t 
on Rost famous throughout the edlieie bateel world, for its beautiful parti- 
_ colored tourmalines. - 
t When at Haddam, about a year since, one of the € quarry men, showed me 
a black crystal nearly an inch in diameter ; which he informed me, had been 
considered coltumbite. It was black lie; but the summits of. two of its 
opposite pyramids being wanting, i was not able. 
is fact, not as doubting at all the existence of columbite at Haddam. 
for this is established upon the au ity; but e collector, w 
t spot, on his guard, lest he should be cr aa hay in the specimens 
him, since both the tances occu r in the chrysoberyl rock and 
ed. The spin 
aoe lle; ot thn, the col a an opinion of Se 
ryrtr mane which may aus Be formed the fact, that I never have met =< 
of it, among th mie africa bo b fa blasts of this roc 
“ae Eee} “28 at different times. . 
