280 Major Delafield and Dr. Bigsby on the 
parallel to the surface of the Lake, and terminates at 
a thickness of one foot. Where it begins it consists of the 
compact crystallized variety, but the direction of the crys- 
tals is so irregular, and their combination so close and di- 
versified, that distinct crystals cannot be obtained. The 
vein terminates in the foliated _ fibrous ehicks of which 
the accompanying specimen is a 
n the massive end of the vein was a small opening that 
led toa cavity filled with distinet crystals. J enlarged it 
sufficiently to admit light, and obtain its contents. The 
cavity was of about three feet diameter and circular. _ Its 
arch was beautifully jetted with pendent crystals differing in 
size and lustre. 
rom all other parts of the cavity they were detached. i 
found them mixed with some dirt, and in a greater quantity 
than it would seem could have been required to cover the 
cireumference of the cavity. They varied in weight from 
ounces to six pounds ; in transparency from the per-: 
fectly transparent, to the opaque ; in lustre from the dull to 
the a re in — from the snow white to the dark 
blue and greenish 
~The tabular eae of six sides with summit of four 
sides aon and are the most transparent. 
simens* I send you, will, I believe, shew this min- 
eral in alli its varieties as there found, and give I trust, a sat- 
isfactory view of its form, colour, lustre; and — 
I hope they may reach you in safety, and prove of some 
interest. Be pleased to accept them with 7 oor respect- 
ful remembrances, and believe me 
our very obedient servant, 
JAS. DELA 
LAFIELD. 
To B. Stuuiman, Esq. 
Extract of a letter addressed to the Editor, from Dr. Joan J. 
Biessy, M. D. of the British Medical Staff. 
Four miles from Put-in-Bay harbour at the upper end of 
Lake Erie, and at a similar distance from the nearest main- 
* Prof. D cena this mineral upon the same Island in 1819; 
but did ot, think, the great vein, The Sulphate e of Strontian Is 
= 1 fthe Basse Islands ; on the 
bouring main shore ; ; oom on somie of the Islands in the Detroit. gies b 
