30

BISCUITS.

acetic for the alkalis, combines with a portion of them to form bicarbonates,fall to the bottom of the vessel in which the mixture is made. The supernatant a ?,' e n,being separated by decantation, the residuary bicarbonate is to be pressed in.washed with ice-cold water, and dried. This ingenious process may be pracds o! .the chamber chemist, but will not afford the bicarboRates at so cheap a rate as tdinary modes of manufacture. sU b-

BIKDLIME. All the parts of the misletoe contain a peculiar viscid -ha’i' . a sstance, which they yield by decoction, particularly of the bark and green portion ’ [Salso from the expressed juice of the bark or berries, when it is kneaded, with theunder water. The birdlime is thus obtained in the form of a white opaq® e Wsticking to the fingers. It may also be extracted from the berries of the misl e turemeans of ether, repeatedly applied, digested with them. It dissolves at first aof green wax and birdlime, but afterward birdlime alone. By distilling oil' thethe birdlime remains colorless and pure. Birdlime may be considered as a k 1 ^ oIviscid resin which does not dry, and resembling in this respect an ointment ol ^il-lard and rosin melted together—the old basilicon of the surgeon. Alcohol, eve ^ e ,ing hot, dissolves hardly any birdlime; but merely its waxy impurities, which g j s0posites in flocks on cooling. It is soluble in the oils of rosemary and turpentine, g j nin petroleum. Heated with the ley of caustic potash, it forms a compound solalcohol. Nitric acid converts it into oxalic acid, and into a fat which solidifi e . s- , 0 j u creMacaire has examined a substance ^rhich exudes from the receptacle and j, e

of the atractylis gnmmifera, and describes it as the pure matter of birdlime, ^ aI1 dstyles viscine. It is said to be composed in 100 parts of 75-6 carbon, 9 - 2hyd lr vfv> le15-2 oxygen. Common birdlime may be regarded as a mixture of viscine, v o , u j c e,mucilage, and vinegar. The young shoots of the ficus elastica afford a milkJwhich is viscine, while the old branches afford a juice rich in caoutchouc. paki n °BISCUITS. For the following account of the mechanical system °* g ra nbbiscuits for the royal navy, I am indebted to the ingenious inventor, ThomasEsq., of Gosport. " jj s h» s

Ships’ biscuits are now made by machinery; and one of the reasons for th ebeen that the manual preparation of them was too slow and too costly ihaseaV”!last war. A landsman knows very little of tlie true value of a biscuit: with rea gon sbiscuit is the only bread that lie eats for months together. There are many c oii'why common loaves of bread could not be used during a long voyage : hecau ^ iftaining a fermenting principle, they would soon become musty and unfit f°f gll l)j eCt made previous to the vovage; while the preparation of them on board ship , lS t i ir o!igh'to insuperable objections. Biscuits contain no leaven, and, when well baked

_ . 4 - +1__XT'_.i _ v'i 3 i.i'

out, they suffer little change during a long voyage.

The allowance of biscuit to eaclTseaman on board a queen’s ship is a P oU ra j(averaging six biscuits to the pound). The supply of a man-of-war for seve dim'is, consequently, very large; and it often happened during the last war thaj oa dsW erculty of making biscuits fast enough was so great, that at Portsmouth wagon-unpacked in the streets and conveyed on board ships. rward

We shall now describe the mode of making biscuits by hand; and a * te g ns and _*of the improved method. The bakehouse at Gosport contained nine drive 1 ’/* aeach was attached a gang of five men—the “ turner,” the “ mate,” the ^ ater W e ,“ breakman,” and the “ idleman.” The requisite proportions of flour an w hol e u j,put into a large trough, and the “ driver,” with his naked arms, mixed ^ aS th etogether in the form of dough—a very laborious operation. The d° u » n thistaken from the trough and put on a wooden platform called the break se f

form worked a lever called the break-staff, five or six inches in diamcte^,^, aI1 d tfeet long ; one end of this was loosely attached by a kind of staple to the 0 ver tbreakman, riding, or sitting on the other end, worked this lever to an j, a d be<-?dough, by an uncouth jumping or shuffling movement. When the d °ttf the 1%kneaded by this barbarous method into a thm sheet, it was removed to ^ e n br°board, and cut into slips by means of an enormous knife; these slips '"’*7 cu j ar fort® ^ jinto pieces, each large enough for one biscuit, and then worked into a , c or ]ana®,. a0 jtthe hand. As each biscuit was shaped it was handed to a secon bis

stamped the king’s mark, the number of the oven, &c., on the biscui • ^ purp**was then docked, that is, pierced with holes by an instrument adapte was

The finishing part of the process was one in which remarkable ? e , n( j the h a .played. A man stood before the open door of the oven, having in his j n th e 0 r

of a long shovel called a peel, the other end of which was lying an( j jerk e ^

Another man took the biscuits as fast as they were formed and stamp® > ^ a fw a 5 s t j,cthrew them into the oven with such undeviating accuracy that they s y e o vCl ^on the peel. The man with the peel then arranged the biscuits side . th^ I »whole floor of the oven. Nothing could exceed (in manual laboi a

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