COL 
COL 
del of pure, constant, and delicate atlacli- 
meut. See Aves, Plate IV. fig. 7. 
C. niigratoria, or the American migra- 
tory pigeon. These birds pass the sum- 
mer in the northern parts of North Ame- 
rica, and on tlie approach of winter move 
towards the southern. They build in trees, 
and feed principally upon acorns, and mast 
of every description. They are also ex- 
tremely fond of rice and corn. They pass 
in tlieir periodical migrations in docks, 
stated to extend in length two miles, and a 
quarter of a mile in width; occasionally 
alighting in the course of their journey, and 
covering the foliage of considerable woods. 
During what is called their flight time, the 
common people of the country easily knock 
them from their roosts, and find them a 
very nourishing and pleasant, as well as 
cheap article of food. In Louisiana it is a 
common entertainment in an evening, in 
which ladies frequently participate, to en- 
ter the woods frequented by these birds, 
and burn a small quantity of sulphur under 
the trees on which they are lodged. Stu- 
pefied by this application, they almost im- 
mediately quit their hold, and drop lifeless 
to the ground, whence they are picked up 
in quantities. 
C. cenas inhabits old turrets, and rocky 
banks of Europe and Siberia, fig. 2. 
COLUMBATES. 
COLUMBIC add 
See CoLDMBiuM. 
COLUMBIUM, in mineralogy and che- 
mistry. Mr. Hatchet, in examining some 
minerals in the British Museum, observed 
one which attracted his attention, from its 
resemblance to chromate of iron. On ana- 
lysing it, he found it to be composed of a 
metallic acid, united with oxide of iron ; 
and this acid, by farther experiments, was 
found to differ in its properties from every 
other. Mr. Hatchet did not succeed in re- 
ducing it to the metallic state. To the 
metal, however, which he supposed to be 
its basis, he gave the name of Columbiura, 
as the ore affording it was the produce of 
America. The mineral which afforded this 
metallic acid is of a dark brownish-grey 
colour ; its lustre is vitreous, inclining to 
metallic : its fracture imperfectly lamel- 
lated : it is moderately hard and very 
brittle ; its particles are not attracted by 
the magnet : its specific gravity is 5.9. 
From this mineral Mr. Hatchet extracted 
the peculiar matter which may be named 
columbic acid. The coluinbic acid is of a 
pure white coloitr, and not extremely 
heavy ; it has scarcely any taste, nor does it 
appear to be soluble in boiling water, but, 
when placed on litmus paper, nrixed with 
distilled water, soon renders tlie paper red. 
From tire acid solutions of columbic 
acid, the alkalies throw it down in the form 
of a white flocculent precipitate. Prussiate 
of potash changes the colom- to an olive- 
green, and a precipitate of the same colour 
is gradually formed. Tincture of galls pro- 
duces a deep orange-coloured precipitate, 
especially when there is not too great an ex- 
cess of acid present. Zinc immersed in 
the solution, gives rise to a white precipi- 
tate. The fixed alkalies combine readily 
both in the humid and in the dry way witli 
columbic acid, forming with it salts called 
columbates. When fused with it, a com- 
pound is formed, which is soluble in water ; 
and if the alkali be in the state of carbo- 
nate, the carbonic acid is disengaged during 
the fusion with effervescence. When a so- 
lution of potash is boiled on it, a quantity is 
dissolved; the solution, which has a consi- 
derable excess of alkali, affords, by gentle 
evaporation, a white salt in shining scales, 
having a disagreeable acrid flavour, not so- 
luble very readily in cold water, but, when 
dissolved, the solution is permanent. 
Nitric acid added to it precipitates the co- 
lumbic acid. Prussiate of potash and tinc- 
ture of galls produced no change; but 
when with either of them a few drops of 
muriatic acid were added, precipitates si- 
milar to those produced by these re-agents 
in the acid solutions, appeared an olive 
green with the one, and an orange-coloured 
precipitate wdth the other. Hydro-sul- 
phuret of ammonia produced a reddish 
brown precipitate. 
This substance is possessed of properties 
different from any of the known metals or 
metallic oxides or acids ; for although in 
some qualities it approaches to titanium, 
tungsten, or to molybdena, it differs from 
then), and from all the others, particularly 
in the precipitates it affords with prussiate 
of potash and tincture of galls, in not com- 
bining with ammonia, and in being insolu- 
ble, and unalterable with regaj-d to colour 
by nitric acid. 
COLUMELLA, in botany, a genus of 
the Syngenesia Superflua class and order : 
receptacle naked, cellular ; seeds crowned 
with a toothed margin ; calyjc cylindrical, 
imbricate ; florets of tlie ray undivided. 
One species, found at the Cape. 
COLUMN, a round pillar, made to sup- 
port and adorn a building, and composed of 
a base, a shaft, and a capital. 
