250 Prof. Horsford on the Rocks of the Florida Reefs. 
The discrepancies in the analyses of the different specimens of 
the same species are due to the circumstance that different parts 
of the stone plant contain organic matter in unlike proportions ; 
and it is very difficult to procure two specimens which, w 
st stages of its er ieayc When first supplied to me, it was of the cena 
wal bolts pouty st ay. It is now so hard as to yield only to a even b 
Ba 
hammer, and is, beside 
e following analysis made by Everett and Warren, upon "samples “differing b 
ioe feo each other in appearance ie 2 been conducted with great care. They 
vary, it will be seen, an oe from each other 
Dried at a temperature of 100° C. By prolonged ignition. 
I. 11450 gr. lost 0-0890 gr. 0°8270 gr, lost 0-4870 gr. 
IL 153825 gr. lost 01175 gr. 1-9020 gr: lost 0°8000 gr. 
The hydrochloric acid solution left a residue of organic matter. * * 
I, 1:1450 gr. gave 029380 gr. IL 16424 gr. gave 0 2805 gr. 
mass, digested in diluted hydrochloric acid, yielded wey existing sulphate 
upon sees addition of chlorid of barium to the filtrate, sulphate of baryta. 
I. 23380 gr. gave 0'1040 gr. Hi. 15825 gr. gave 0° ue BE pti 
matter by itself, oxydated in nitro-hydrochloric acid, wi addition of 
Five eg Ghicciie of potassa, yielded to chlorid of barium a ee le of sulphate 
_of baryta. 
= 15325 gr. gave 0° oons ae 
n a mixture of fused ni 
ac otra Molded to a4aee o petites and hydrochloric neon a a sabenpere - fla f 
L 23090 gr. gave 0°2850 gr. II, 1/4322 gr. gave 0'1550 gr. 
The hydrochloric acid solution filtered from the ig matter gave a precipitate 
of oxalate of lime, which was determined as carbona: 
I. 08770 gr. gave 04100 gr. 
Expressed in percents, the above determinations give of if 
Water, expelled at 100° C. 
Li (70h pew. IL 766 p.c _». Average, 72 p. & 
Total volatile matier, 
L 4117 p.c IL 42°06 pe. Average, 41'58 p. © 
The following per cents. are estimated upon the substance as dried at 100° C. 
cag oe existing as ange. - soluble in diluted hydrochloric acid. 
L 5.p.c.. AL..09 IL 1:26 p.c. Average, O94 Pe e 
sip in oe matter. 
L 
Total sulphur ‘of the se dtchaiealies 2:39. p. G. : 
Total — by oxydation of the mass, including the organic and inorganic parts. 
lp.¢ 1°84 p.c. Average, 1772p. 
Seisiane by the two methods ole 8 — 205 p. & 
Lime, = - 80°09 p.% 
elas sil oe ne the results of the above determinations with the the quantities 
which Prof. Dana justly conceives to be inadequate to vibe changes aseribed, we hav® 
