are not identical with those from invertebrate animals. The melanosis or blackening of insect blood, for instance, is due to the oxidation of a chromogen, the pigment produced being known as a uranidine. In some sponges a somewhat similar pigment has been noticed. Other pigments have been described, such as actiniochrome, echinochrome, pentacrinin, antedonin, polyperythrin (which appears to be a haematoporphyrin), the floridines, spongioporphyrin, &c., which need no mention here; all these pigments can only be distinguished by means of the spectroscope.
Most of the pigments are preceded by colourless substances known as “chromogens,” which by the action of the oxygen of the air and by other agencies become changed into the corresponding pigments. In some cases the pigments are built up in the tissues of an animal, in others they appear to be derived more or less directly from the food. Derivatives of chlorophyll and lipochromes especially, seem to be taken up from the intestine, probably by the agency of leucocytes, in which they may occur in combination with, or dissolved by, fatty matters and excreted by the integument. In worms especially, the skin seems to excrete many effete substances, pigments included. No direct connexion has been traced between the chlorophyll eaten with the food and the haemoglobin of blood and muscle. Attention may, however, be drawn to the work of Dr E. Schunck, who has shown that a substance closely resembling haematoporphyrin can be prepared from chlorophyll; this is known as phylloporphyrin. Not only does the visible spectrum of this substance resemble that of haematoporphyrin, but the invisible ultra-violet also, as shown by C. A. Schunck.
The reader may refer to E. A. Schäfer’s Text-Book of Physiology (1898) for A. Gamgee’s article “On Haemoglobin, and its Compounds”; to the writer’s papers in the Phil. Trans. and Proc. Roy. Soc. from 1881 onwards, and also Quart. Journ. Micros. Science and Journ. of Physiol.; to C. F. W. Krukenberg’s Vergleichende physiologische Studien from 1879 onwards, and to his Vorträge. Miss M. I. Newbigin collected in Colour in Nature (1898) most of the recent literature of this subject. Dr E. Schunck’s papers will be found under the heading “Contribution to the Chemistry of Chlorophyll” in Proc. Roy. Soc. from 1885 onwards; and Mr C. A. Schunck’s paper in Proc. Roy. Soc. vol. lxiii. (C. A. MacM.)
COLSTON, EDWARD (1636–1721), English philanthropist,
the son of William Colston, a Bristol merchant of good position,
was born at Bristol on the 2nd of November 1636. He is generally
understood to have spent some years of his youth and manhood
as a factor in Spain, with which country his family was long
connected commercially, and whence, by means of a trade in
wines and oil, great part of his own vast fortune was to come.
On his return he seems to have settled in London, and to have
bent himself resolutely to the task of making money. In 1681,
the date of his father’s decease, he appears as a governor of
Christ’s hospital, to which noble foundation he afterwards gave
frequently and largely. In the same year he probably began to
take an active interest in the affairs of Bristol, where he is found
about this time embarked in a sugar refinery; and during the
remainder of his life he seems to have divided his attention pretty
equally between the city of his birth and that of his adoption. In
1682 he appears in the records of the great western port as advancing
a sum of £1800 to its needy corporation; in 1683 as
“a free burgess and meire (St Kitts) merchant” he was made a
member of the Merchant’s Hall; and in 1684 he was appointed
one of a committee for managing the affairs of Clifton. In 1685
he again appears as the city’s creditor for about £2000, repayment
of which he is found insisting on in 1686. In 1689 he was chosen
auditor by the vestry at Mortlake, where he was residing in an
old house once the abode of Ireton and Cromwell. In 1691, on
St Michael’s Hill, Bristol, at a cost of £8000, he founded an almshouse
for the reception of 24 poor men and women, and endowed
with accommodation for “Six Saylors,” at a cost of £600, the
merchant’s almshouses in King Street. In 1696, at a cost of
£8000, he endowed a foundation for clothing and teaching 40
boys (the books employed were to have in them “no tincture
of Whiggism”); and six years afterwards he expended a further
sum of £1500 in rebuilding the school-house. In 1708; at a cost
of £41,200, he built and endowed his great foundation on Saint
Augustine’s Back, for the instruction, clothing, maintaining
and apprenticing of 100 boys; and in time of scarcity, during
this and next year, he transmitted “by a private hand” some
£20,000 to the London committee. In 1710, after a poll of four
days, he was sent to parliament, to represent, on strictest Tory
principles, his native city of Bristol; and in 1713, after three
years of silent political life, he resigned this charge. He died
at Mortlake in 1721, having nearly completed his eighty-fifth
year; and was buried in All Saints’ church, Bristol.
Colston, who was in the habit of bestowing large sums yearly for the release of poor debtors and the relief of indigent age and sickness, and who gave (1711) no less than £6000 to increase Queen Anne’s Bounty Fund for the augmentation of small livings, was always keenly interested in the organization and management of his foundations; the rules and regulations were all drawn up by his hand, and the minutest details of their constitution and economy were dictated by him. A high churchman and Tory, with a genuine intolerance of dissent and dissenters, his name and example have served as excuses for the formation of two political benevolent societies—the “Anchor” (founded 1769) and the “Dolphin” (founded 1749),—and also the “Grateful” (founded 1758), whose rivalry has been perhaps as instrumental in keeping their patron’s memory green as have the splendid charities with which he enriched his native city (see Bristol).
See Garrard, Edward Colston, the Philanthropist (4to, Bristol, 1852); Pryce, A Popular History of Bristol (1861); Manchee, Bristol Charities.
COLT, SAMUEL (1814–1862), American inventor, was born on
the 19th of July 1814 at Hartford, Connecticut, where his
father had a manufactory of silks and woollens. At the age of
ten he left school for the factory, and at fourteen, then being
in a boarding school at Amherst, Massachusetts, he made a
runaway voyage to India, during which (in 1829) he constructed
a wooden model, still existing, of what was afterwards to be the
revolver (see Pistol). On his return he learned chemistry
from his father’s bleaching and dyeing manager, and under the
assumed name “Dr Coult” travelled over the United States
and Canada lecturing on that science. The profits of two years
of this work enabled him to continue his researches and experiments.
In 1835, having perfected a six-barrelled rotating
breech, he visited Europe, and patented his inventions in London
and Paris, securing the American right on his return; and the
same year he founded at Paterson, New Jersey, the Patent
Arms Company, for the manufacture of his revolvers only.
As early as 1837 revolvers were successfully used by United
States troops, under Lieut.-Colonel William S. Harney, in
fighting against the Seminole Indians in Florida. Colt’s scheme,
however, did not succeed; the arms were not generally appreciated;
and in 1842 the company became insolvent. No revolvers
were made for five years, and none were to be had when General
Zachary Taylor wrote for a supply from the seat of war in
Mexico. In 1847 the United States government ordered 1000
from the inventor; but before these could be produced he had
to construct a new model, for a pistol of the company’s make
could nowhere be found. This commission was the beginning
of an immense business. The little armoury at Whitneyville
(New Haven, Connecticut), where the order for Mexico was
executed, was soon exchanged for larger workshops at Hartford.
These in their turn gave place (1852) to the enormous factory
of the Colt’s Patent Fire-Arms Manufacturing Company, doubled
in 1861, on the banks of the Connecticut river, within the city
limits of Hartford, where so many millions of revolvers with
all their appendages have been manufactured. Thence was
sent, for the Russian and English governments, to Tula and
Enfield, the whole of the elaborate machinery devised by Colt
for the manufacture of his pistols. Colt introduced and patented
a number of improvements in his revolver, and also invented
a submarine battery for harbour defence. He died at Hartford
on the 10th of January 1862.
COLT’S-FOOT, the popular name of a small herb, Tussilago Farfara, a member of the natural order Compositae, which is
