COR 
first distinguished from other minerals by 
Dr. Black. In 1768, Mr. Berry, a lapidary 
in Edinburgh, received a box of it from Dr. 
Anderson of Madras. Dr. Black ascertain- 
ed that these specimens differed from all 
the stones known to Europeans ; and, in 
consequence of its hardness it obtained the 
name of adamantine spar. It is found in 
Hindostan, not far from the river Cavery, 
which is south of Madras, in a rocky 
matrix of considerable hardness, partaking 
of the nature of the stone itself. It occurs 
also in China, and in Ceylon, Ava, &c. The 
Count de Bournon pointed out the resem- 
blance between this mineral and the sap- 
phire, in a dissertation published by him 
and Mr. Greville in the Philosophical Trans- 
actions for 1798, and suggested it as proba- 
ble that corundum may be only a variety of 
the sapphire ; and that the seeming differ- 
ence in their ingredients is owing to the 
impurity of those specimens of corundum 
which have hitherto been brought to Eu- 
rope. This conjecture has been since con- 
firmed by a subsequent dissertation of Bour- 
non, and the chemical analysis of Clienevix. 
Werner subdivides it into two species, 
namely, corundum, and adamantine spar ; 
but, in reality, they seem to be only varie- 
ties, or, at most, subspecies of the same 
species. The chief difference exists in the 
colours. 
Corundum has been found in India, in the 
Carnatic, and on the coast of Malabar. It 
occurs massive, in rolled pieces, and crys- 
tallized ; crystals the same as in sapphire ; 
colour greenish- white, passing into greenish- 
grey and asparagus-green, sometimes pearl- 
grey, which passes into flesh-red; surface 
rough; fracture foliated; specific gravity 
3.7 to 4.2. 
Mr. Chenevix obtained the following 
constituents from the specimens of the co- 
rundums, which he subjected to chemical 
analysis. 
IMPERFECT CORUNDUM. 
From the 
From 
From 
From 
Carnatic. 
Malabar. 
China. 
Ava. 
Silica 
.. 5.O.... 
, 7.0..., 
. 5.25... 
.. 6.5 
Alumina.. 
.. 91.0.... 
, 86.5..., 
, 86.50.. 
.. 87.0 
Iron 
. 4.0... 
. 6.50.. 
.. 4.5 
97.0 
97.5 
98.25 
98.0 
Loss . 
.. 2.5 
2.5 
1.75 
2.0 
100 
100 
100 
100 
.T,.' .11. 
sssasr. 
COR 
PERFECT CORUNDUM. 
Silica 
Blue, or 
Sapphire. 
Red, or 
Oriental Ruby 
7.0 
Alumina... 
90.0 
Iron 
1.2 
97.25 
Loss.... 
... 1.75 
100 
100 
CORUSCATION, a glittering, or gleam 
of light issuing from any thing. It is chiefly 
used for a flash of lightening darting from 
the clouds in time of thunder. See Mete- 
orology. 
CORYLUS, in botany, English liasel, or 
nut-tree, a genus of the Monoecia Polyan- 
dria class and order. Natural order of 
Araentace®. Essential character : male 
calyx one-leaved, three-cleft, scale-form, 
one-flowered ; corolla none ; stamens eight. 
Female calyx two-leaved, lacerated ; corolla 
none; styles two; nut ovate. There are 
three species with many varieties, C. avel- 
lana, common hasel nut tree, is properly a 
shrub, the trunk of which is covered with a 
whitish cloven bark, which is smooth on the 
branches, frequently of a bay colour, spot- 
ted with white ; the shoots are sometimes 
hairy, ash-coloured, and green, with white 
tubercles. The male catkins appear in 
autumn, and wait for the expansion of the 
female gems in spring ; the styles are of a 
bright red colour, long, and setaceous j the 
flowering branches, especially those which 
bear the fertile flowers, are set with short 
fine hairs, terminating in globules ; the cat- 
kins are in pairs, and of a yellowish-green 
colour. 
CORYMBIUM, in botany, a genus of 
the Syngenesia Motiogamia class and order. 
Natural order of Composit® Discoide®. 
Cinarocephal®, Jussieu. Essential charac- 
ter: calyx two-leaved, one-flowered, pris- 
matic; corolla one-petalled, regular; seed 
one, below the corolla, woolly. There are 
four species, all natives of the Cape of Good 
Hope. 
CORYNOCARPUS, in botany, a genus 
of tire Pentandria Monogynia class and or- 
der. Natural order of Berberides, Jussieu. 
Essential character: nectaries five, petal- 
shaped, alteniate with the petals, glandu- 
lous at the base. One species, found at 
New Zealand. 
CORYPHA, in botany, appendix palma. 
Natural order of Palms. Essential charac- 
