enotes the melting its ore, after being first burnt to destroy the mundie.

Machines for Blowing the Air into Furnaces. See the article Furnace.

Blowing, among gardeners, denotes the action of flowers, whereby they open and display their leaves. In which sense, blowing amounts to much the same with flowering or blossoming.

The regular blowing season is in the spring; though some plants have other extraordinary times and manners of blowing, as the Glastonbury thorn. Divers flowers flowers also, as the tulip, close every evening, and blow again in the morning. Annual plants blow sooner or later, as their seeds are put in the ground; whence the curious in gardening sow some every month in summer, to have a constant succession of flowers. The blowing of roses may be retarded by shearing off the buds as they put forth.

**BLUBBER,** denotes the fat of whales and other large sea-animals, whereof is made train-oil. It is properly the **adip** of the animal; it lies immediately under the skin, and over the muscular flesh. In the porpoise, it is firm and full of fibres, and invests the body about an inch thick. In the whale, its thickness is ordinarily six inches; but, about the under lip, it is found two or three feet thick. The whole quantity yielded by one of these animals ordinarily amounts to 40 or 50, sometimes to 80 or more, hundred weight. The use of blubber to the animal seems to be partly to poise the body, and render it equidistant from the water; partly to keep off the water at some distance from the blood, the immediate contact whereof would be apt to chill it; and partly also for the same use that clothes serve us, to keep the fish warm, by reflecting or reverberating the hot streams of the body, and so redoubling the heat; since all fat bodies are, by experience, found less sensible of the impressions of cold than lean ones. Its use in trade and manufactures is to furnish train-oil, which it does by boiling down. Formerly this was performed ashore, in the country where the whales were caught; but of late the fishers do not go ashore; they bring the blubber home flowed in casks, and boil it down here.

**Sea-Blubber.** See Medusa.

**BLUE,** one of the seven colours into which the rays of light divide themselves when refracted through a glass prism.—For an account of the particular structure of bodies by which they appear of a blue colour, see the article Chromatics.—The principal blues used in painting are Prussian blue, bice, Saunders blue, azure, or smalt, verditer, &c.; for the preparation of which, see Colour-Making.—In dyeing, the principal ingredients for giving a blue colour are indigo and wood. See Dyeing.

**Blue Colour of the Sky.** See Sky.

**Blue Bird.** See Motacilla.

**Blue Fish.** See Coryphaena.

**Blue Japan.** Take gum-water, what quantity you please, and white lead a sufficient quantity; grind them well upon a porphyry; then take flagging size what quantity you please, of the finest and best smalt a sufficient quantity; mix them well; to which add, of your white lead, before ground, to much as may give it a sufficient body. Mix all these together to the consistence of a paint.

**BLUING,** the art or art of communicating a blue colour to bodies otherwise destitute thereof. Landrefes blue their linen with smalt; dyers their stuffs and wools with wood or indigo.

**Bluing of Metals** is performed by heating them in the fire, till they assume a blue colour; particularly practised by gilders, who blue their metals before they apply the gold and silver leaf.

**Bluing of Iron,** a method of beautifying that metal sometimes practised; as for mourning buckles, swords, and the like. The manner is thus: Take a piece of grind-stone or whet-stone, and rub hard on the work, to take off the black scurf from it; then heat it in the fire; and as it grows hot, the colour changes by degrees, coming first to light, then to a darker gold colour, and lastly to a blue. Sometimes also they grind indigo and fallad-oil together; and rub the mixture on the work with a woollen rag, while it is heating, leaving it to cool of itself. Among sculptors we also find mention of bluing a figure of bronze, by which is meant the heating of it, to prepare it for the application of gold-leaf, because of the bluish cast it acquires in the operation.

**BLUFF-HEAD,** among sailors. A ship is said to be bluff-headed, that has an upright stern.

**BLUNDERBUSS,** a short fire-arm with a wide bore, capable of holding a number of bullets at once.

**BOA,** in zoology, a genus of serpents, belonging to the order of amphibia. The characters of this genus are, that the belly and tail are both furnished with scuta. The species are ten, viz. 1. The constrictor, has 150 scuta on the belly, and 40 on the tail; the head is broad, very convex, and has poison-bags in the mouth, but no fangs, for which reason its bite is not reckoned poisonous: the body is silh-coloured, interspersed with large dusky spots; and the tail is about a third of the length of the body. This serpent is found in Carolina. 2. The canina, has 203 scuta on the belly, and 77 on the tail; it is greenish, and variegated with white belts. It is a native of America, and lodges in the hollow trunks of trees, and is about two feet long. The bite of the canina is not poisonous. 3. The hippocale, is of a dull yellow colour, and is found in Asia. It has 179 scuta on the belly, and 120 on the tail.

4. The constrictor, has 240 scuta on the belly, and 60 on the tail. This is an immense animal; it often exceeds 36 feet in length; the body is very thick, of a dusky white colour, and its back is interspersed with 24 large pale irregular spots; the tail is of a darker colour; and the sides are beautifully variegated with pale spots. Besides, the whole body is interspersed with small brown spots. The head is covered with small scales, and has no broad lamina betwixt the eyes, but has a black belt behind the eyes. It wants the large dog-fangs, and of course its bite is not poisonous. The tongue is fleshy, and very little forked. Above the eyes, on each side, the head rises high. The scales of this serpent are all very small, roundish, and smooth. The tail does not exceed one eighth of the whole length of the animal. The Indians, who adore this monstrous animal, use the skin for cloaths, on account of its smoothness and beauty. There are several of these skins of the above dimensions preserved, and to be seen in the different museums of Europe, particularly in the library and botanic garden of Upsal in Sweden, which has of late been greatly enriched by count Grillinborg. The flesh of this serpent is eaten by the Indians, and the negroes of Africa. Pilo, Margraave, and Kempfer, give the following account of its method of living and catching its prey. It frequents caves and thick forests, where it conceals itself, and suddenly darts out upon strangers, wild beasts, &c. When it chuses a tree for its watching-place, it supports itself by twisting its tail round the trunk or a branch, and darts down upon sheep, goats, tigers, or any animal that comes within... in its reach. When it lays hold of animals, especially any of the larger kinds, it twirls itself several times round their body, and by the vast force of its circular muscles bruises and breaks all their bones. After the bones are broke, it licks the skin of the animal all over, besmearing it with a glutinous kind of saliva. This operation is intended to facilitate deglutition, and is a preparation for swallowing the whole animal. If it be a flag, or any horned animal, it begins to swallow the feet first, and gradually sucks in the body, and last of all the head. When the horns happen to be large, this serpent has been observed to go about for a long time with the horns of a flag sticking out from its mouth. As the animal digests, the horns putrify and fall off. After this serpent has swallowed a flag or a tiger, it is unable for some days to move; the hunters, who are well acquainted with this circumstance, always take this opportunity of destroying it. When irritated, it makes a loud hissing noise. This serpent is said to cover itself over with leaves in such places as flags or other animals frequent, in order to conceal itself from their sight, and that it may the more easily lay hold of them. See Plate LVIII.

5. The murina, has 254 scuta on the belly, and 65 on the tail. The colour of it is a light blue, with round spots on the back. It is a native of America, and its bite is not poisonous. 6. The scytale, has 250 scuta on the belly, and 70 on the tail. The body is ash-coloured and bluish, with round black spots on the back, and black lateral rings edged with white. This serpent is a native of America; and, like the constrictor, tho' not so long, twirls itself about sheep, goats, &c. and swallows them whole. 7. The cenchrus, has 265 scuta on the belly, and 57 on the tail. It is of a yellow colour, with white eye-like spots. It is a native of Surinam, and its bite is not poisonous. 8. The ophrias, has 281 scuta on the belly, and 64 on the tail; the colour is nearly the same with that of the constrictor, but browner. The place where this serpent is to be found is not known; but its bite is not venomous. 9. The eaydris, has 270 scuta on the belly, and 105 on the tail. The colour is a dusky white, and the teeth of the lower jaw are very long; but its bite is not poisonous. It is a native of America. 10. The hortulana, has 290 scuta on the belly, and 128 on the tail. It is of a pale colour, interspersed with livid wedge-like spots. It is a native of America, and its bite is not poisonous.