280 Major Delafetd 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 erys+ 
tals is so irregular, and their combination so close and di- 
versified, that distinct crystals cannot be obtained. ‘The 
vein terminates in the foliated and fibrous variety, of which 
the accompanying specimen is a part. 
In the massive end of the vein was a small opening that 
led toa cavity filled with distinct crystals. 1 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 i in 
size and lustre. 
From all other parts of the cavity they were ihinseldedl i 
found them mixed with some dirt, and in a greater quantity 
than it would seem could have been required to cover the 
circumference of the cavity.’ They varied in weight from 
six ounces to six pounds ; in transparency from the per- 
fectly transparent, to the opaque ; in lustre from the dull to 
the resplendent ; in colour from the snow w nine to the dark 
blue and greenish blue. 
The tabular crystals of six sides with summit of four 
sides prevail, and are the most transparent. 
The specimens* I send you, will, T believe, shew this min- 
eral in allits varieties as there found, and give I trust; a sat- 
isfactory view of its form, colour, lustre; and cleavage. 
[ hope they may reach you in safety, and prove of some 
interest. Be pleased to accept them with my most respect+ 
ful remembrances, and believe me 
Your very obedient servant, 
JAS. DELAFIELD. 
To B. Sirtm1an, Esq. 
Extract of a letter addressed to the E dite from Dr. Jound: 
Biessy, M. D. of the British Medical Staff. 
Four miles from Put-in-Bay harbour at the upper end of 
ake Erie, and at a similar distance from the nearest main- 
* Prof. Douglass discovered this mineral upon the same Island in 1819; 
but did not, I think, notice the great vein. ‘The Sulphate of Strontian is 
found inall parts of this Island, and others of the Basse Islands ; on the neigh- 
bouring main shore ; and on some of the Islands in the Detroit River. 
sia 0 
