sisting of a steel-bow, fixed at the end of a short shaft or stock, furnished with a string or trigger. It serves to expel bullets, stones, arrows, and darts. CROTALUS, the rattle-snake, a genus of serpents furnished with poisonous fangs. The serpents of this family seldom bite except when irritated, or for the purpose of securing their prey. Their possession of the fascinating power which has been attributed to them is uncertain; the fact, that small birds, squirrels and leverets, descend spontaneously, from the branches of the tree under which the rattle snake lies, and are devoured by it, seems to be generally admitted, though it is very difficult to be accounted for. The more common opinion is that the animals thus devoured are in the first place terrified by the noise of the snake's rattle, and hence lose all power of self-government, or continue to fly from branch to branch till they are so exhausted as to be compelled to fall down within its reach. The rattle consists of hollow, hard, dry, and semitransparent bones resembling in some measure, the shape of the human os sacrum: the tip of every uppermost bone runs within two of the bones below it; by which contrivance they have not only a moveable coherence, but also are enabled to make a more multiplied sound, each bone hitting against the other two at the same time. The number of joints in the rattle of individuals is various, from five to forty. The poisonous secretion is discharged from the fangs of the dog, teeth, or tusks placed without the upper jaws, after the manner of the viper, and after the first time the animal seems progressively to lose its power of poisoning, till it has had time to recruit itself by a respite of some hours: so that the

second bite, if given immediately after the first, does not prove so injurious, the third still less so, and the fourth does, perhaps, scarcely any mischief at all.

CROTON, or wild ricinus, is a botanical genus containing 51 species, of which may be noticed, the croton tinctorium, or turnsole, which is used as a colouring matter in various arts and chemical processes: the substance thus used is found between the empalement and the seeds: croton sebiferum, or tallow tree, is a native of China, about the size of a cherry tree. The fruit is enclosed in a pod, and consists of three round white grains of the size of an ordinary hazel nut, with a small stone in the interior. From the kernels or expressed oil, the Chinese obtain tallow, of which they make their candles.

CROTOPHAGA, a genus of birds, natives of South America, noticed on account of a curious peculiarity belonging to the females, several of which lay their eggs in the same nest, which is the united work of them all. Each contributes, likewise, her share to the general process of incubation, and to provide food for the common family. These birds are said to pick out the acari from the backs of cattle infested with them, for which purpose, they lie down spontaneously.

CROWN, an ornament worn on the head by kings, sovereign princes, and nobles, as a mark of dignity. In heraldry, it is used for the representation of that ornament in the mantling of an armory to express the dignity of persons. The Romans had va rious kinds of crowns, as 1. The oval crown, made of myrtle, and bestowed on victorious generals: 2.

The naval crown, composed of a circle of gold, with ornaments representing the beaks of ships, and given to the officers or men who first boarded an enemy's ship. 3. The crown given as a reward to bim who first forced the enemy's entrenchments. 4. The mural crown, given to him who first mounted the wall of a besieged place, and there lodged a standard. 5. The civic crown, made of the branch of a green oak, and given him who had saved the life of a citizen. These and other crowns were given as marks of honour, and upon competitions with rivals for rank and dignity often determined the preference in their favour.

CROWN-Office. The court of king's bench is divided into the plea-side and the crown side. In the plea side it takes cognizance of civil causes, in the crown side it takes cognizance of criminal causes, and is therefore called the crown office. In the crown office are exhibited informations in the name of the king, of which there are two kinds, 1. Those filed ex officio by the king's attorney general. These are properly the king's own suits. 2. Those in which, though the king is the nominal prosecutor, yet, it is done at the instance of some private person or common informer; these are usually filed by the master of the crown office.

CRUCIBLE, a vessel made of earth, and so tempered and baked as to indure the greatest fire. It is used in chemical operations, and by workers in gold and silver. See CHEMICAL Apparatus.

CRUISER, from the German kruiss, "across,” a small armed vessel that sails to and fro in quest of the enemy, and to secure those of its own nation. CRUSADE. See CROISADE.

VOL. II.

CRUOR, Sometimes signifies the blood in general; sometimes only the venous blood, and at others extravasated or coagulated blood; but the word is most frequently used for the red globules of blood, in contradistinction to the limpid or serous part.

CRUSTACEOUS fish, are those covered with shells consisting of several pieces or scales, as those of crabs, lobsters, &c. These are generally softer than the shells of the testaceous fish, which consist of a single piece, and commonly thicker and stronger than the former, such as those of the oyster, scal-lop, cockle, &c. The crustacea consist almost entirely of the three tribes, viz. cancer, oniscus, and monoculus.

CRYPTOGAMIA, the 24th class of vegetables in the Linnean system; comprehending those whose fructification is concealed or inconspicuous, as ferns, mosses, liverworts, and mushrooms. See BOTANY.

CRYSTAL, a species of stones of the quartz kind, belonging to the siliceous class. When no accidental circumstance has interrupted the crystalization (for it must once have been in a soft state), it is always of an hexagonal (six-sided) angular form, pointed at both ends. Crystal is found of various colours. It is frequently cut; and lustres, vases, and toys, are made of this, as of other beautiful stones. In the imperial collection at Vienna, there is a pyramidical, crystal vase, two ells in height, wholly cut out of one crystal.-The formation of crystals is one of the most ordinary operations of nature. This is evident from the sparry STALACTITÆ (resemblances of icicles) in the arches of modern buildings particularly Westminster bridge, the

roofs of the arches of which were filled with these spars within a year after they were built.

CUBE, a regular solid body, consisting of six square and equal sides, and the angles all right, and therefore equal.

CUBE-root of any number or quantity, is such a number or quantity as, if multiplied by itself and then the product thence arising by that number or quantity, being the cube-root-this last product shall be equal to the number or quantity whereof it is the cube root: thus, 2 is the cube-root of 8; because two times two is 4, two times 4 is 8.

CUCKOW, a genus of birds belonging to the order of pies or pica. The habit, peculiar to this bird, of laying its egg in the nest of others of different species, is well known; but that the young one is no sooner hatched than all the eggs or young of its foster parents are pushed out to perish together, either entangled about the bush which contains the nest, or scattered on the ground under it, is not, perhaps, of equal notoriety. The following little narrative is extracted from a paper in the Philosophical Transactions, by the honourable Daines Barrington: "A hedge-sparrow built her nest in a hawthorn bush in a timber-yard. After she had laid two eggs, a cuckow dropped in a third. The sparrow continued laying as if nothing had happened, till she had laid five, her usual number, and then sat. On inspecting the nest, June 20, 1786, I found that the bird had hatched that morning, and every thing but the young cuckow was thrown out. Under the nest, I found one of the young hedge-sparrows dead, and one egg by the side of the nest entangled with the coarse woody