Prof. Horsford on the Source of Lime in Corals: 251. 
pulverized, will present homogeneous powders of the same con- 
itution. 
II. Source of Lime in the Growth of Corals. 
~ Marcet,* as early as 1823, observed carbonate of lime in the sea- 
water near Portsmouth. Jacksont found it in two specimens of 
sea-water furnished by the United States Exploring poe seb 
one from 600 feet, and the other from 2,700 feet below the sur- 
face. I. Davyt found the sea-water of Carlisle Bay, Barbadoes, 
to contain about ;,1,>th part of carbonate of lime. ‘There was 
found scarcely a trace near the volcanic island of Fayal. White]| 
is of the opinion that it fails only near the surface ; but the elab- 
orate analysis by Bibra$, of no less than ten specimens taken 
eg ae from a depth of avholes feet, but in one instance from a 
by s spontaneous aration of a considerable body of sea-water thrown, with its 
mingled coral mud a’ a animal matter, into an inland basin, at the rare juncture of 
favorable high ieee and tide. A single layer of the surface rock is ne residue left 
by evapora ation of the water mingled with c oral nud and animal matter, thrown uP 
in spray from the dacing of the waves, or carried up by flood- ee. an left. by ev: 
poration in the int bee ween the two tides. This will accoun ts sit belicn 
_ for its © pee neces as well as/ in depressions pe “ve abrupt 
, for its interstratied einen with the coarse coral sand ; indeed, for all 
the phases and peculiarities of it which are presented 1 in the extensive suite of col- 
lections submitted to 
In addition to the changes enumerated in ‘the ne japer as resulting from the 
decay of the animal matter, another may be m The ammonia evolved in 
the process of decomposition, would provi vide haat of lime from the oo aE ae 
Sent in the i he aver a to 
ent in the sea-water. si ient, taking the average of Bibra’s an is 
the chlorid of sodium as 1 to 16, and may be eonceived to have | urnish incon- 
siderable amount of hydrate of lime for the process 0 consolidation 
ana attri the form ig of this crust-rock wh naires more 
prominent — of my investigation, to the action of simple rain-water, aly ving 
the carbonate of lime and again depositing it it evaporation. &] is would ac- 
count for its, oun ence in depressions of the rock, but would not account for its 
occurrence on em iow or on Girtot Filo pes er would it account for the presence 
of Water as raceme 
sentence of the bys nd paragrap es ~e the above — has been replied 
I have sabad no g ation to.the animal matter in corals. 
: ks regard to the ee ‘png ill not be questioned t that hee | ig a great amount 
ut coral reefs. Bibra found 
sition abo 
mister it-varlone stages of decomposition vaieay ie [have, in the 
ogee materi in all the tens peas nde to the parties who a 
r above, repeated the statement made to me by $W. 
specimens, t the age within the und in animal life. That procured 
for analy m withi eys was found ‘exceedingly. offensive from the d decom- 
—— of animal co It tlds ded the od ante 
a total am o c¢ matter 0! pe 
iulas it is difficult to see oe water should fail to i Pe, oom aap it 
vem e iS we hy, April, 1828, oe 
Ari, Jour hy, : ol v, p P 
Phil. ne, 8, XXXY, p.2 ds. | Ib. p- 308. 
Ann. de et de Pharmacie, Lxxvii, 90. 
‘Am, Jo our. Sa (8 a prina 81. 
