418 Analysis of Fowlerite. 
The inference that corals would soon die in bodies of salt 
water wholly cut off from the ocean, because they would thus 
fail of the requisite amount of sulphate of lime, may or may not 
be just; but it follows for another reason, even more obvious, viz. : 
the excessive saltness of the water from evaporation in the dry 
seasons of the year, and also its excessive freshness in the rainy 
seasons,—either condition unfitting it for the growth of marine 
species. 
In the analyses of corals given in Prof. Horsford’s paper, no 
mention is made of the presence of fluorine or phosphoric acid. 
This will not be received as any reason for discrediting Prof. Sil- 
liman’s determinations of these ingredients. The author has in 
his hands plates of glass that were etched by this chemist with 
the date of his experiments, from fluorine afforded by corals from 
the Pacific.* 
Prof. Horsford by ascertaining the specific gravity of the coral 
of the interior of a Meandrina and comparing it with that of the 
exterior, endeavors to determine whether the interior is absorbed 
for the formation of the new coral. In very many species, as we 
have had occasion often to observe, the process is the reverse. 
The exterior is comparatively porous, while the interior is solid 
or nearly so, the secretions of lime in progress filling up even the 
interstices occupied by the animal membranes, as the animal dies 
at its inner extremity. The process of absorption as far as 1s 
known does not appear to belong to the lower and dying extrem- 
ity of the polyp; this’ function is performed by the parts above 
from the food and sea water taken into the stomach and internal 
cavity of the animal. 
Arr. XL.—Analysis of Fowlerite; by W. Camac, M.D. 
Havine some good specimens of Fowlerite at command, I _ 
subjected the mineral to a careful analysis in order to determine 
its formula. It was broken into small pieces, which were selected 
with care, in order to avoid the presence of the least trace of any 
other associated minerals. The external characters of cleavage, 
hardness, é&c., agreed with the description usually given of it, 
except that the streak was of a delicate salmon color. 
The analysis was made partly by fusion with carbonate of 
soda, for the ingredients generally, and partly by fluohydric acid 
to determine the alkali, as well as some of the constituents by way 
_—— 
this Journal, [2], p. 249, was a Nullipor 
if 
- BL, learn from Prof. Agassiz, that the Millepora analyzed by Prof. Horsford, 
e. 
