190 
Proceedings of the Royal Irish Academy. 
Addendum B. 
Minerals to which reference is made in the Report on Molecular Dissociation 
hy Heat. 
Mineral. 
1 &2. 
Calcite and 
Arragonite. 
3. 
Hematite. 
4. 
Specu- 
larlron 
Ore. 
5. 
Ochre 
(yellow). 
6. 
Brown Iron 
Ore. 
7. 
Corundum. 
8 . 
Diaspore. 
AXJTHORITY. 
Spillerand 
Smith. 
TiCHBORNE. 
Dick. 
J". L. Smith. 
Smith, 
rer. Oxide, 
Ferrous Ox- 
ide, . . 
Chromic 
Oxide, 
Alumina, . 
Manganese 
Oxide, . 
Lime, 
Magnesia, 
Sulphuric 
Acid, . . 
Carbonic 
Acid, 
Phosphoric 
Acid, 
Chlorine. . 
Silica, . . 
Iron Py- 
rites, 
Water, 
Organic 
matter, . 
Remarks, . 
56- 
44- 
Calcite, or 
rhombo- 
hedral 
form, spe- 
cific gra- 
vity 2-72 
H. 3. Ar- 
ragonite, 
or rhom- 
bic carbo- 
nate, 2-9 
to 3-8 H 
3'5 Ar- 
ragonite 
seems to 
be formed 
at a higher 
tempera- 
ture than 
calcite, 
and is 
more prone 
to take the 
colloidal 
form (glo- 
bular or 
radial 
crystal- 
lization). 
94-23 90-94 
•63" 
•23 ^25 
•65 ^99 
•09 ^24 
•78 
4^9 6-68 
•03" 
99 • 
tracs. 
1-47 
The remain- 
der of this 
mineral 
nearly 
consisted 
of hy- 
drated 
ferric ox- 
ide, and a 
portion of 
clay. 
52-83 
•81 
14-61 
5-7 
•28 
18-14 
•32 
4-75 
1-30 
The average 
of twenty- 
five ana- 
lyses of 
brown iron 
ore give 
•032 per 
cent. of 
sulphur, 
exclusive 
of pyrites. 
These ores 
f r 6 gh tly 
take the 
globular 
form. 
93-12 
1- 62 
0^91 
•96 
2- 86 
The water 
in sap- 
phire, ru- 
by, orien- 
tal topaz, 
&c., ave- 
rages 2 per 
cent. ; 
emery, 4 
per cent. 
•63 
84-02 
•43 
14-81 
Associated 
with the 
varieties 
of corun- 
dum. 
