346 Filter and Prepared Charcoal of M. Dumont. 
found in the calcareous rocks of the West Indies, and the entrance 
to the cavities in which they reside is far less than the shells them- 
selves, a proof that they have the power of perforating limestone, 
for they must have entered the rocks when very young and gradual- 
ly enlarged their habitations as they increased in size. For this fact 
I am indebted to General Parker who presented me a specimen 
which he himself had procured by breaking the rock in which it was 
concealed. 
~Pholas costata. Lin. The same gentleman bought in the Ha- 
vanna market fine living specimens of this Pholas, far larger than are 
generally met with on our coast. -Dead shells are common on all 
the coasts of the Middle and Southern States, but I believe a living 
specimen has never been obtained here. They must certainly how- 
ever, burrowin the sand at or near low water mark. “a 
~Cardium-Mortoni. This shell, described and figured by mein the 
6th. vol. Jour. Acad. of Natural Sciences, was at that time supposed to 
be peculiar to the Eastern States, and especially the shores of Long 
Island Sound. Specimens however have lately been sent from the 
extreme Southern States ; Dr. Blanding obtained it in East Florida, 
and Dr. Hutchins in the vicinity of Pensacola. Neem 
Arr. XVIII.—Report on the Filter and Prepared Charcoal of M. 
Dumont,* by MM. Serullas, Bussy, and Derosne. Translated 
from the Journal de Pharmacie, by Franxurn R. Sra, of Phi- 
ladelphia. ‘ ie 
To the Sociétie de Pharmacie de Paris. 
~ Gentlemen,—M. Dumont, an experienced manufacturer of beet 
sugar, called your attention to a filter of his invention, and to a pre~ 
pared charcoal, which he employs in the bleaching of syrups, and 
you charged MM. Serullas, Bussy, and myself, (Derosne,) to give 
you-an account thereof. isl gee 
_ The discovery of the decolorizing property of charcoal, is due to 
Lowitz of St. Petersburg, who however did not remark the difference 
in activity between vegetable and animal charcoal. ‘Therefore the 
former only was employed in the sugar refineries for the decolora~ 
tion of syrup. In 1811, M. F iguier of Montpellier ascertained that 
* ‘This paper would long sinee have appeared, but for. the accidental cireumstance 
of its having heen mislaid and forgotten. In searching for another document, we 
were glad to recover this. ; é tr SS ee 
