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tare is fuch that a little flour fpread at its mouthis Browned but not burnt, the loaves are de-pofited within, the mouth is clofed up with aniron door, and at the proper time (varyingaccording to the fize of the loaves) the bread iswithdrawn, is replaced on the table and againcovered with a blanket, in order to cool asilowly as poffible; the afhes and adhering flourare then removed with a brufh and the bread isready for fale.

The changes produced upon dough by bakingare very remarkable, nor can they in any degreebe attributed to evaporation, fince the lofs ofweight never ought to exceed -y'o, and is veryoften not greater than In the firft placethe progrefs of fermentation is entirely flopped :the bread may be kept for feveral days withoutexperiencing any alteration, and the firft fign offpontaneous change is its becoming mouldy.Secondly, the tenacious duttility of the doughand its compact texture, are exchanged for amoderately firm and flightly elaftlc confiftence,and a very fpungy texture, in confequence ofthe alterations produced in the gluten by heatand moifture. Thirdly, the fecula or ftarchwhich was merely diffufed through the doughwithout being in any degree affected by thepanary fermentation, is combined during thebaking with a portion of water into a ftiff gelly,like common ftarch when boiled with water, andthus renders the bread confiderably more tranf-parent than dough, as well as more digeftible.

Rye and barley are the only fubftances befideswheat that are capable of being made intobread, becaufe they alone contain gluten enoughto admit of being formed into a moderatelytenacious pafte with water. Even in thefe how-ever, the proportion of gluten is too fmall toafford light bread without the ufe of an acidferment to difengage the proper quantity ofcarbonic acid; fo that they can never for thepurpofe of the baker be at all comparable towheaten flour.

BRECCIA. Brecht, Fr.

This term was firft we believe employed bythe Italian ftatuaries to denote thofe kinds ofmarble which are really or apparently compofedof angular fragments of marble cemented to-gether by a pofterior infiltration of calcareousfpar or marble. Some of the French mine-ralogifts have adopted the term and extendedits meaning, fo as to include any ftony mafscompofed of angular fragments confolidated bya cement. Hence they fubdivide the genericterm brkhe into calcareous, magnefian, filiceous,

and argillaceous, and difcriminate it from amyg-daloid or poudingue (from the Englifh pudding-ftone) by reftrifting the meaning of this latter,to ftony maffes formed of rounded, pebbles im-bedded in a cement. Neither this term nor anyanalogous to it is admitted into the nomen-clature of the German mincralogifts.BRIMSTONE. See Sulphur.

BRONZE. See Copper alloys of.

BRUNSWICK-GREEN. a Braunfchweigifhegrim , Germ.

This is a pigment ufed by feme of the German artifts, and is prepared as follows. Take onepart of muriated ammonia and make a faturatedfolution of it in cold water, put it into a tumb-ler, or any other convenient glafs veffel, andadd to it three parts of copper clippings; coverthe mouth of the veffel with a piece of gauzeto keep out the dull, and place it in a warmfituation, fo that in a few days the moifturewill be evaporated. The muriat of ammoniaprefently begins to be decompofed by the copper,which in its turn is corroded and converted toa green oxyd. When the whole is evaporated-to drynefs, digeft it in two or three fuccelfiveportions of fpirit of wine, as long as any greenoxyd is taken up, add the folutions togetherand drive off the liquor by a gentle heat; the.refidue is a pure dark-green fub-muriat of cop-per, known in the fhops by the name of refined:Brunfwick-green.

BUTTER. See Milk.

BUTTERS MINERAL. A name given bythe old chemifts to fome of the fublimed metallic.muriats, on account of their foft butyraceous.texture when recently prepared. There arefour metals which afford mineral butters, viz..Antimony, arfenic, bifmuth, and tin, and the.peculiar properties of each of thefe falts arementioned under the refpeclive metals. The.circumftances in which they all agree are thefollowing. They are formed by fublimation ;their confiftence is like that of common butter,in warm weather, and a gentle heat refolves.them into a denfe oily-looking liquor; they aredecompofable by being dropped into pure water,a copious precipitation of. white oxyd takingplace. When the French nomenclature .was-newly introduced they were called oxymuriatsbut it appears from later experiments that the.excefs of oxygen which they contain over thecommon muriats, is..combined not with the acid-but with the metal.

BUTTERS VEGETABLE. Such of the.vegetable expreffed oils as require a greater heat

* Grcn. Syft. Handb. iii. p. 334-.