in a general sense, denotes an agitation of the air, whether performed with a pair of bellows, the mouth, a tube, or the like. Butchers have a practice of blowing up veal, especially the loins, as soon as killed, with a pipe made of a sheep's shank, to make it look larger and fairer.

**Blowing of Glass**, one of the methods of forming the various kinds of works in the glass manufacture. It is performed by dipping the point of an iron blowing pipe in the melted glass, and blowing through it with the mouth, according to the circumstances of the glass to be blown. See **Glass**.

**Blowing of Tin**, denotes the melting its ore, after being first burnt to destroy the mudic. 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 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 equiponderant to the water; partly to keep off the water at some distance from the blood, the immediate contact whereof would be apt to chill it; 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 woad. 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 ifgnglass 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, so much as may give it a sufficient body. Mix all these together to the consistence of a paint.

**Blue-John,** among miners, a kind of mineral which has lately been fabricated into vases and other ornamental figures. It is of the same quality with the cubic spar, with respect to its fusibility in the fire. It looses its colour, and becomes white in a moderate heat: the weight of a cubic foot of the bluest kind is 3180 ounces, and that of the least blue is 3140 ounces. This substance began first to be applied to use about 18 years ago at one of the oldest mines in Derbyshire, called Odin mine, probably from its being dedicated to Odin the great god of the northern nations, at the foot of a high mountain called Mam-Tor in Crafleton. Here the greatest quantities are still found; the largest pieces are sold for 9l. a ton, the middle-sized for 6l. and the least for 50s.

**Prussian Blue.** See Chemistry-Index.

**BLUING,** the act or art of communicating a blue colour to bodies otherwise destitute thereof. Landrefers blue their linen with smalt; dyers their stuffs and wools with woad 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-flone or whit-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 it 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.

**Blushing,** a suffusion or redness of the cheeks, excited by a sense of shame, on account of consciousness of some failing or imperfection.