Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/326

296&#93; 296] BLO Ls sufficient. " The first inqxtiry to be made," says M. Bergmann, " js, what a substance contains, not how much." Experiments with the blow-pipe have this advantage over those conducted in crucibles, that we can distinctly see all the phenomena from beginning to end; by which means we obtain an illus- tration of the series of operations and their causes. BLOWING, an agitation of the air by means of a pair of bellows, the mouth, &c. Butchers have a very pernicious custom of blowing meat, to deceive the buyer. The sudden change of veal and lamb in particular may, in some degree, be attributed to this cause. It is also a common practice to blow poul- try, and all sorts of fish, except those of the shell kind. The me- thod of blowing fish, especially cod and whiting, is, by placing the end of a quill, or a tobacco-pipe, at the vent, and making a hole with a pin under the fin which is next the gill ; consequently the fish appears large ajid fall, but when dressed will be flabby, and little else but skin and bones. By placing the thumb on each side of the vent, and pressing it hard, the air may be perceived to escape, and this impo- sition be detected. As the venders of provisions, who are guilty of such disgusting prac- tices, may at the same time be in- fected >s i tli the most loathsome dis- eases, the articles thus polluted should he rejected as being unfit for consumption. Indeed, the per- nicious tendency of" blowing meat is obvious, and ought therefore to be discouraged by every class of purchaser:,, while it claims the se- and vigorous interference of •the public magistrate. Blowing, in botany, is the gra- BLU dual and perfect expansion of flowers. Blowing of Glass, is performed by dipping the end of an iron blow- pipe into melted glass, and bloAving into it. See Glass. BLUBBER, the fat of the whale and other aquatic animals. It lies immediately under the. skin. In the porpoise it is firm, fibrous, and about an inch thick ; in the whale, it is commonly six inches in thick- ness. Formerly, the blubber was boiled down into train-oil on the shores of Greenland, and other places, where tire whales were caught ; but it is now brought home in casks, and undergoes that process in Britain. The quantity of blubber yielded by a whale is forty, fifty, nay sometimes, eighty hundred weight. BLUE, is one of the seven co- lours of Nature, into which the rays of light divide themselves when refracted through a prism. The principal blues used in painting are, Prussian blue, bice, Saunders' blue, azure or smalt, verditer, &c. ; for the preparation of which, see Co- lour-making. In dyeing, the principal ingredients which afford a blue colour, are indigo and woad, — See also Dyeing. The Dutch Hue, commonly callt ed Turnsol, may be prepared by the following process : The kind of lichen called Arabic, or, in de- fault of it, the large oak moss, be-? ing dried and cleansed, ought to be reduced to a powder, and by the Assistance of a press, forced through a sieve, the holes of which should be small. This powder should be then mixed in a trough with an alkali called vetas, or the ashes of v ine lees, in the proportion of one- third ashes, and two-thirds lees. Tliis composition being moistened witft