W. M. Carpenter on the Muscles in the Glass Snake. 89 
ments at least are an essential part of its constitution; and they 
have been separated from the general mass by a segregation of like 
atoms under well known principles, and it may be, arranged 
anew, in some cases, according to their affinities. Fluoride of 
calcium may erystallize out when under water, without much or 
any heat; and it is an interesting fact that this fluoride has been 
lately proved by Mr. G. Wilson, to be soluble, to some degree, 
in pure cold water.* Mr. G. Wilson has also shown that fluor- 
ides actually exist in seawater, as had been suggested by Mr. Sil- 
liman, some months before the discovery, in his memoir on the 
composition of corals. Apatite and chondrodite require heat, as 
they are found only in granular limestones. The chondrodite is 
not supposed to exist as such in coral, but to form from the mutual 
action of its elements, (which are present) during the slow action 
of the heat that gives the crystalline character to the limestone. 
The magnesia of magnesian limestones is not attributable to 
the corals, as the proportion obtained by the analyses is less than 
one per cent.t It is derived probably from a foreign source ; and 
this may be true, in part at least, for the magnesia of the chon- 
drodite, although there is enough of this constituent present for 
a large amount of this mineral. The silica may also be in part 
foreign, or may proceed from the earthy impurities which were 
mixed with the limestone at its formation. 
New Haven, May Ist, 1846. 
igs 
Arr. XII.—Description of a peculiar arrangement of muscles 
in the Glass Snake, (Ophisaurus); by W. M. Carrenter, A. 
M., M. D., Professor in the Medical College of Louisiana. 
Born in the Old and the New Worlds, there are species of rep- 
tiles called Glass Snakes, (serpent a verre,) on account of their 
extreme fragility. These animals, belonging to different species, 
appertain however to the same group. The animal called by 
this name in Europe, is the Anguis fragilis of Linnzus, whilst in 
this country, several species of Ophisaurus are confounded, by the 
people, under this common name. 
ME ssa ie 
*See Chem. Gazette, No.85, May 1846, p. 183; and beyond, in this volume. 
tSee this Journal, New Series, i, 189, 198. 
Srconp Series, Vol. II, No. 4.—July, 1846. 12 
