BRAZIL-WOOD

( Bois de Fernambouc , Fr.; Brasilienholz , Germ.) This dye-wood derives its name from the part of America whence it was first imported. It has also the names Fernambuca, wood of Saint Martha, and of Sapan, according to the places which produce it. Linnæus distinguishes the tree which furnishes the Brazil wood by the name of Cæsalpinia crista . It commonly grows in dry places among rocks. Its trunk is very large, crooked, and full of knots. It is very hard, susceptible of a fine polish, and sinks in water. It is pale when newly cleft, but becomes red on exposure to the air. It has different shades of red and orange. Its goodne is determined particularly by its density. When chewed, a saccharine taste is perceived. It may be distinguished from red saunders wood, as the latter does not yield its colour to water. Boiling water extracts the whole colouring matter of Brazil-wood. If the ebullition be long enough continued, it a umes a fine red colour. The residuum appears black. In this case, an alkali may still extract much colouring matter. The solution in alcohol or ammonia is still deeper than the preceding. The decoction of Brazil-wood, called juice of Brazil, is observed to be le fit for dyeing when recent, than when old or even fermented. By age it takes a yellowish-red colour. For making this decoction, Hellot recommends to use the hardest water; but it should be remarked, that this water deepens the colour in proportion to the earthy salts which it contains. After boiling this wood reduced to chips, or, what is preferable, to powder, for three hours, this first decoction is poured into a cask. Fresh water is poured on the wood, which is then made to boil for three hours, and mixed with the former. When Brazil-wood is employed in a dyeing bath, it is proper to enclose it in a thin linen bag, as well as all the dye woods in general. Wool immersed in the juice of Brazil takes but a feeble tint, which is speedily destroyed. It must receive some preparations. The wool is to be boiled in a solution of alum, to which a fourth or even le of tartar is added, for a larger proportion of tartar would make the colour yellowish. The wool is kept impregnated with it for at least eight days, in a cool place. After this, it is dyed in the Brazil juice with a slight boiling. But the first colouring particles that are deposited, afford a le beautiful colour; hence it is proper to pa a coarser stuff previously through the bath. In this manner a lively red is procured, which resists pretty well the action of the air. Brazil-wood is made use of for dyeing silk what is called false crimson, to distinguish it from the crimson made by means of cochineal, which is much more permanent. The silk should be boiled at the rate of 20 parts of soap per cent., and then alumed. The aluming need not be so strong as for the fine crimson. The silk is refreshed at the river, and pa ed through a bath more or le charged with Brazil juice, according to the shade to be given. When water free from earthy salts is employed, the colour is too red to imitate crimson; this quality is given it by pa ing the silk through a slight alkaline solution, or by adding a little alkali to the bath. It might, indeed, be washed in a hard water till it had taken the desired shade. To make deeper false crimsons of a dark red, juice of logwood is put into the Brazil bath after the silk has been impregnated with it. A little alkali may be added, according to the shade that is wanted. To imitate poppy or flame colour, an an not to ground is given to the silk, deeper even than when it is dyed with cart ham us. It is washed, alumed, and dyed with juice of Brazil, to which a little soap water is usually added. The colouring particles of Brazil wood are easily affected, and made yellow by the action of acids. They thus become permanent colours. But what distinguishes them from madder and kermes, and approximates them to cochineal, is their reappearing in their natural colour, when they are thrown down in a state of combination with alumina, or with oxide of tin. These two combinations seem to be the fittest for rendering them durable. It is requisite, therefore, to inquire what circumstances are best calculated to promote the formation of these combinations, according to the nature of the stuff. The astringent principle, likewise, seems to contribute to the permanence of the colouring matter of Brazil wood; but it deepens its hue, and can only be employed for light shades. The colouring particles of Brazil wood are very sensible to the action of alkalies which give them a purple hue; and there are several proce es in which the alkalies, either fixed or volatile, are used for forming violets and purples. But the colours obtained by these methods, which may be easily varied according to the purpose, are perishable, and po e but a transient bloom. The alkalies appear not to injure the colours derived from madder, but they accelerate the destruction of most other colours. In England and Holland the dye-woods are reduced to powder by means of mills erected for the purpose. The bright fugitive red, called fancy red, is given to cotton by Nicaragua, or peach wood, a cheap kind of Brazil wood. The cotton being scoured and bleached, is boiled with sumach. It is then impregnated with a solution of tin (at 5° Baumé, according to Vital is). It should now be washed slightly in a weak bath of the dyeing wood, and lastly, worked in a somewhat stale infusion of the peach or Brazil wood. When the temperature of this is lukewarm, the dye is said to take better. Sometimes two succe ive immersions in the bath are given. It is now wrung out, aired, washed in water, and dried. M. Vital is says, that his solution of tin is prepared with two ounces of tin and a pound of aqua regia made with two parts of nitric acid at 24° Baumé, and three parts of muriatic acid at 22°. For a rose colour, the cotton is alumed as usual, and washed from the alum. It then gets the tin mordant, and is again washed. It is now turned through the dye-bath, an operation which is repeated if nece ary. For purple a little alum is added to the Brazil bath. 1. For amaranth, the cotton is strongly galled, dried, and washed. 2. It is pa ed through the black cask (tonneau noir), see Black Dye , till it has taken a strong grey shade. 3. It receives a bath of lime water. 4. Mordant of tin. 5. Dyeing in the Brazil wood bath. 6. The two last operations are repeated. Dingler has endeavoured to separate the colouring matter of the different sorts of Brazil wood, so as to obtain the same tint from the coarser as from the best Pernambuco. His proce consists in treating the wood with hot water or steam, in concentrating the decoction so as to obtain 14 or 15 pounds of it from 4 pounds of wood, allowing it to cool, and pouring into it two pounds of skim milk; agitating, then boiling for a few minutes, and filtering. The dun colouring matters are precipitated by the coagulation of the caseous substance. For dyeing, the decoctions must be diluted with water; for printing they must be concentrated, so that 4 pounds of wood shall furnish only 5 or 6 pounds of decoction, and the liquor may be thickened in the ordinary way. These decoctions may be employed immediately, as by this treatment they have acquired the same property as they otherwise could get only by being long kept. A slight fermentation is said to improve the colour of these decoctions; some ground wood is put into the decoction to favour this proce . As gelatine produces no precipitate with these decoctions, they consequently contain no tannin. Gall-nuts, however, sumach, the bark of birch or alder, render the colour of Brazil wood more durable, upon alumed linen and cotton goods, but the shade is a little darker. In dyeing wool with Pernambuco, the temperature of the bath should never be above 150° Fahr., since higher heats impair the colour. According to Dingler and Kurrer, bright and fast scarlet reds may be obtained upon wool, by preparing a decoction of 50 pounds of Brazil wood in three succe ive boils, and setting the decoction aside for 3 or 4 weeks in a cool place; 100 pounds of the wool are then alumed in a bath of 22 pounds of alum and 11 pounds of tartar, and afterwards rinsed in cold water. Meanwhile we fill two-thirds with water, a copper containing 30 pails, and heated to the temperature of 150° or 160° F. We pour in 3 pailfuls of the decoction, heat to the same point again, and introduce 30 pounds of wool, which does not take a scarlet, but rather a crimson tint. This being removed, 2 pails of decoction are put in, and 30 pounds of wool which becomes scarlet, but not so fine as at the third dip. If the dyer strengthens the colour a little at the first dip, a little more at the second, and adds at the third and fourth the quantity of decoction merely nece ary, he will obtain an uniform scarlet tint. With 50 pounds of Pernambuco 1000 pounds of wool may be dyed scarlet in this way, and with the deposits another 100 may be dyed of a tile colour. An addition of weld renders the colour faster but le brilliant. Karkutsch says the dye may be improved by adding some ox-gall to the bath. In dyeing cotton the tannin and gallic acid are two nece ary mordants, and the colour is particularly bright and durable, when the cloth has been prepared with the oily proce of Turkey red. It is said that stale urine heightens the colour of the Brazil dye when the ground wood is moistened with it. The quantity of Brazil or Nicaragua wood imported into the United Kingdom in 1835, was 6,242 tons, whereof 1,811 were exported; of Brazilietto 230 tons. The duty upon the first article is 5 s. per ton. leavened or fermented dough of wheat or rye flour, at a proper heat. It is the principal food of highly civilized nations. The skilful preparation of this indispensable article constitutes the art of the Baker. Dough baked without being fermented constitutes cakes or biscuits; but not bread strictly speaking. Pliny informs us, that barley was the only species of corn at first used for food; and even after the method of reducing it to flour had been discovered, it was long before mankind learned the art of converting it into cakes. Ovens were first invented in the East. Their construction was understood by the Jews, the Greeks, and the Asiatics, among whom baking was practised as a distinct profe ion. In this art, the Cappadocians, Lydians, and Phœnicians, are said to have particularly excelled. It was not till about 580 years after the foundation of Rome, that these artisans pa ed into Europe. The Roman armies, on their return from Macedonia, brought Grecian bakers with them into Italy. As these bakers had hand mills beside their ovens, they still continued to be called pistores , from the ancient practice of bruising the corn in a mortar; and their bakehouses were denominated pistoriæ . In the time of August us there were no fewer than 329 public bakehouses in Rome; almost the whole of which were in the hands of Greeks, who long continued the only persons in that city acquainted with the art of baking good bread. In nothing, perhaps, is the wise and cautious policy of the Roman government more remarkably displayed, than in the regulations which it imposed on the bakers within the city. To the foreign bakers who came to Rome with the army from Macedonia, a number of freedmen were a ociated, forming together an incorporation from which neither they nor their children could separate, and of which even those who married the daughters of bakers were obliged to become members. To this incorporation were entrusted all the mills, utensils, slaves, animals, every thing, in short, which belonged to the former bakehouses. In addition to these, they received considerable portions of land; and nothing was withheld, which could a ist them in pursuing, to the best advantage, their highly prized labours and trade. The practice of condemning criminals and slaves, for petty offences, to work in the bakehouse, was still continued; and even the judges of Africa were bound to send thither, every five years, such persons as had incurred that kind of chastisement. The bakehouses were distributed throughout the fourteen divisions of the city, and no baker could pa from one into another without special permi ion. The public granaries were committed to their care; they paid nothing for the corn employed in baking bread that was to be given in large to the citizens; and the price of the rest was regulated by the magistrates. No corn was given out of these granaries except for the bakehouses, and for the private use of the prince. The bakers had besides private granaries, in which they deposited the grain, which they had taken from the public granaries for immediate use; and if any of them happened to be convicted of having diverted any portion of the grain to another purpose, he was condemned to a ruinous fine of five hundred pounds weight of gold. Most of these regulations were soon introduced among the Gauls; but it was long before they found their way into the more northern countries of Europe. Bor rich i us informs us that in Sweden and Norway, the only bread known, so late as the middle of the 16th century, was unleavened cakes kneaded by the women. At what period in our own history the art of baking became a separate profe ion, we have not been able to ascertain; but this profe ion is now common to all the countries in Europe, and the proce of baking is also nearly the same. The French, who particularly excel in the art of baking, have a great many different kinds of bread. Their pain bis , or brown bread, is the coarsest kind of all, and is made of coarse groats mixed with a portion of white flour. The pain bis blanc , is a kind of bread between white and brown, made of white flour and fine groats. The pain blanc , or white bread, is made of white flour, shaken through a sieve after the finest flour has been separated. The pain mollet , or soft bread, is made of the purest flour without any admixture. The pain chal and , or customers’ bread, is a very white kind of bread, made of pounded paste. Pain chapelé , is a small kind of bread, with a well-beaten and very light paste, seasoned with butter or milk. This name is also given to a small bread, from which the thickest crust has been removed by a knife. Pain cornu , is a name given by the French bakers to a kind of bread made with four corners, and sometimes more. Of all the kinds of small bread, this has the strongest and firmest paste. Pain à la reine , queen’s bread, pain à la Sigovie , pain chapelé , and pain cornu , are all small kinds of bread, differing only in the lightne or thickne of the paste. Pain gruau is a small very white bread made now in Paris, from the flour separated after a slight grinding from the best wheat. Such flour is in hard granular particles. In this country we have fewer varieties of bread, and these differ chiefly in their degrees of purity. Our white or fine bread is made of the purest flour; our wheaten bread, of flour with a mixture of the finest bran; and our household bread, of the whole substance of the grain without the separation either of the fine flour or coarse bran. We have also symnel bread, manchet or roll bread, and French bread, which are all made of the purest flour from the finest wheat; the roll bread being improved by the addition of milk, and the French bread by the addition of eggs and butter. To these may be added gingerbread, a cake made of flour, with almonds, liquorice, aniseed, rose-water, and sugar or treacle; and mastlin bread, made of wheat and rye, or sometimes of wheat and barley. We have various kinds of small bread, having various names, according to their various forms. They are, in general, extremely light, and are sweetened with sugar, currants, and other palatable ingredients. In Scotland there is a cake called short bread , made from a pretty thick dough, enriched with butter, sweetened with sugar, and seasoned with orange peel, or other kinds of spices. The proce of making bread is nearly the same in all the countries of modern Europe; though the materials of which it as composed vary with the farinaceous productions of different climates and soils. The flour of wheat is most generally employed for this purpose, wherever that vegetable can be reared. This flour is composed of a small portion of mucilaginous saccharine matter, soluble in cold water, from which it may be separated by evaporation; of a great quantity of starch, which is scarcely soluble in cold water, but capable of combining with that fluid by means of heat; and an adhesive gray substance called gluten, insoluble in water, ardent spirit, oil, or ether, and resembling an animal substance in many of its properties. Flour kneaded with water, forms a tough rather indigestible paste containing all the constituent parts which we have enumerated. Heat produces a considerable change on the glutinous part of this compound, and renders it more easy of mastication and digestion. Still, however, it continues heavy and tough, compared with bread which is raised by leaven or yeast. Leaven is nothing more than a piece of dough, kept in a warm place till it undergoes a proce of fermentation; swelling, becoming spongy, or full of air bubbles, at length disengaging an acidulo-spirituous vapour, and contracting a sour taste. When this leaven is mingled in proper proportions with fresh-made dough, it makes it rise more readily and effectually than it would do alone, and gives it at the same time a greater degree of firmne . Upon the quality of the leaven employed, the quality of the bread materially depends. The principal improvement which has been made on bread in modern times, is the substitution of yeast or barm in place of common leaven. This yeast is the viscid froth that rises to the surface of beer, in the first stage of its fermentation. When mixed with the dough, it makes it rise much more speedily and effectually than ordinary leaven, and the bread is of course much lighter, and freer from that sour and disagreeable taste which may often be perceived in bread raised with leaven, either because too much is mingled with the paste, or because it has been allowed to advance too far in the proce of fermentation. Bread properly raised and baked, differs materially from unleavened cakes, not only in being le compact and heavy, and more agreeable to the taste, but in losing its tenacious and glutinous qualities, and thus becoming more salutary and digestible. We po e several analyses of wheat flour. Ordinary wheat ( triticum hybernum mixed with triticum turgidum ) contains, according to the analyses made by Vauquelin of several species of wheat flour, the following substances :— | Species of Wheat. | Water. | Gluten. | Starch. | Sugar. | Gum. | Bran. | Total. | Water of dough. | | French wheat flour | 10·0 | 10·96 | 71·49 | 4·72 | 3·32 | - | 100·49 | 50·3 | | Hard wheat of Ode a flour | 12·0 | 14·55 | 56·50 | 8·48 | 4·90 | 2·3 | 98·73 | 51·2 | | Soft wheat of Ode a flour | 10·0 | 12·00 | 62·00 | 7·56 | 5·80 | 1·2 | 98·42 | 54·8 | | Same sort of flour | 8·0 | 12·10 | 70·84 | 4·90 | 4·60 | - | 100·41 | 37·4 | | Same sort of flour | 12·0 | 7·30 | 72·00 | 5·42 | 3·30 | - | 100·02 | 37·2 | | Wheat of the French bakers | 10·0 | 10·20 | 72·80 | 4·20 | 2·80 | - | 100·00 | 40·6 | | Flour of the Paris hospitals (2d quality) | 8·0 | 10·30 | 71·20 | 4·80 | 3·60 | - | 97·90 | 37·8 | | Ditto (3d quality) | 12·0 | 9·02 | 67·78 | 4·80 | 4·60 | 2·0 | 100·21 | 37·8 | The following table of analyses merits also a place here. | Species of Flour. | Water. | Gluten. | Starch. | Sugar. | Gummi- gluten. | Albu- men. | Bran. | | Flour of the triticum spelt a | 1 | 22· | | 74· | | 5· | 50 | 1· | | 1·50 | | | Ditto triticum hybernum | 1 | 24· | | 68· | | 5· | 0 | 1· | | 1·50 | | | Ditto common wheat | - | 12· | 5 | 74· | 5 | 12· | | 2· | | | | | Ditto wheat and rye mixed (mastlin) | 6 | 9· | 80 | 75· | 50 | 4· | 22 | 3· | 28 | - | 1·2 | The first two of the above analyses were made by Vogel, the third by Proust, and the fourth by Vauquelin. Analyses of the flour of some other corns. | Species of Flour. | Starch. | Mucilage. | Gluten. | Albumen. | Sugar. | Husk. | Hordein. | | White oatmeal | 59·00 | 2· | 5 | - | 4·30 | 8·25 | Of a fat oil, 2 | | | Barley meal | 32·00 | 9· | | 3· | - | Of resin, 2 | - | 55 | The first analysis is by Vogel, the second by Proust. It deserves to be remarked, that the flour of Ode a contains a much greater quantity of sugar than the French flour. The substance indicated in the preceding table by the name of gluten, is the gluten of Beccaria, that is to say, a mixture of gluten and vegetable albumen. The gum of wheat is not quite identical with ordinary gum. It is a brown azotised substance, which, when treated by nitric acid, affords no mucic acid, but oxalic acid and the bitter principle of Welter. It contains besides superphosphate of lime. The last column of the first table exhibits the quantity of water nece ary to convert the flour into dough of the ordinary consistence, and it is usually proportional to the quantity of gluten. The hard wheat of Ode a forms an exception in this respect; the reason of the difference being that the starch contained in this flour is not as in ordinary flour in a fine powder, but in small transparent grains, which resemble pounded gum, and absorb le water than pulverulent starch. The triticum monococcon , according to Zenneck, contains in its unsifted flour, 16·334 of gluten and vegetable albumen; 64·838 of starch; 11·347 of gum, sugar, and extractive; 7·481 of husks. The sifted flour affords 15·536 of gluten and vegetable albumen; 76·459 of starch; 7·198 of sugar, gum, and extractive; 0·807 of husky matter. It is difficult to conceive how such great quantities of gluten, albumen, and extractive matter, could disappear in the sifting. The triticum spelt a contains in 100 parts of the finest flour, 22·5 of a soft and humid gluten, mixed with vegetable albumen; 74 of starch, and 5·5 of sugar. Here we have an exce of 2 parts in the 100. Wheat furnishes very little ashes by incineration, not more than 0·15 per cent. of the weight; containing superphosphates of soda, lime, and magnesia. The object of baking is to combine the gluten and starch of the flour into a homogeneous substance, and to excite such a vinous fermentative action, by means of its saccharine matter, as shall disengage abundance of carbonic acid gas in it for making an agreeable, soft, succulent, spongy, and easily digestible bread. The two evils to be avoided in baking are, hardne on the one hand, and pastine on the other. Well-made bread is a chemical compound, in which the gluten and starch cannot be recognized or separated, as before, by a stream of water. When flour is kneaded into a dough, and spread into a cake, this cake, when baked, will be horny if it be thin, or if thick, will be tough and clammy; whence we see the value of that fermentative proce , which generates you sands of little cells in the ma or crumb, each of them dry, yet tender and succulent, through the intimate combination of the moisture. By this constitution it becomes easily soluble in the juices of the stomach, or in other words, light of digestion. It is moreover much le liable to turn sour than cakes made from unfermented dough. Rye, which also forms a true spongy bread, though inferior to that of wheat, consists of similar ingredients; namely, 61·07 of starch; 9·48 of gluten; 3·28 of vegetable albumen; 3·28 of uncrystallizable sugar; 11·09 of gum; 6·38 of vegetable fibre; the lo upon the 100 parts amounted to 5·62, including an acid whose nature the analyst, M. Einhof, did not determine. Rye flour contains also several salts, principally the phosphates of lime and magnesia. This kind of grain forms a dark-coloured bread reckoned very wholesome; comparatively little used in this country, but very much in France, Germany, and Belgium. Dough fermented with the aid either of leaven or yeast, contains little or none of the saccharine matter of the flour, but in its stead a certain portion, nearly half its weight, of spirit, which imparts to it a vinous smell, and is volatilized in the oven; whence it might be condensed into a crude weak alcohol, on the plan of Mr. Hick’s patent, were it worth while. But the increased complexity of the baking apparatus, will probably prove an effectual obstacle to the commercial succe of this project, upon which already upwards of 20,000 l. sterling have been squandered. That the sugar of the flour is the true element of the fermentation preposterously called panary, which dough undergoes, and that the starch and gluten have nothing to do with it, may be proved by decisive experiments. The vinous fermentation continues till the whole sugar is decomposed, and no longer; when if the proce be not checked by the heat of baking, the acetous fermentation will supervene. Therefore if a little sugar be added to a flour which contains little or none, its dough will become susceptible of fermenting, with extrication of gas, so as to make spongy succulent bread. But since this spongine is produced solely by the extrication of gas, and its expansion in the heat of the oven, any substance capable of emitting gas, or of being converted into it under these circumstances, will answer the same purpose. Were a solution of bicarbonate of ammonia obtained by exposing the common sesqui-carbonate in powder for a day to the air, incorporated with the dough, in the subsequent firing it will be converted into vapour, and in its extrication render the bread very porous. Nay, if water highly impregnated with carbonic acid gas be used for kneading the dough, the resulting bread will be somewhat spongy. Could a light article of food be prepared in this way, then as the sugar would remain undecomposed, the bread would be so much the sweeter, and the more nourishing. How far a change propitious to digestion takes place in the constitution of the starch and gluten, during the fermentative action of the dough, has not been hitherto ascertained by precise experiments. Medical practitioners, who derive an enormous revenue from dyspepsia, should take some pains to investigate this subject. Dr. Colquhoun, in his able e ay upon the art of making bread, has shown that its texture when prepared by a sudden formation and disengagement of elastic fluid generated within the oven, differs remarkably from that of a loaf which has been made after the preparatory fermentation with yeast. Bread which has been raised with the common carbonate of ammonia as used by the pastry-cooks, is porous no doubt, but not spongy with vesicular spaces, like that made in the ordinary way. The former kind of bread never presents that air-cell stratification which is the boast of the Paris i an baker, but which is almost unknown in London. I have found it moreover very difficult to expel by the oven the last portion of the ammonia, which gives both a tinge and a taste to the bread. I believe, however, that the bicarbonate would be nearly free from this objection, which operates so much against the sesqui-carbonate of the shops. In opposition to Mr. Edlin’s account of the excellent quality of bread made by impregnating dough with carbonic acid gas [10] , Dr. Colquhoun adduces Vogel’s experiments, which show that such dough, when baked, after having been kept in a warm situation during the usual time, afforded nothing better than a hard cake, which had no resemblance to common bread. Vogel further states, as illustrative of the general nece ity of providing a sufficient supply of disengaged elastic fluid within the dough, before baking it at all, that when he made various attempts to form a well-raised vesicular loaf, within the oven, by mixing flour with carbonate of magnesia, or with zinc filings, and then kneading it into a paste by means of water, acidulated with sulphuric acid, he always met with complete failure and disappointment. Dr. Colquhoun performed a series of well-devised experiments on this subject, which fully confirmed Vogel’s results, and prove that a proper spongy bread cannot be made by the agency of either carbonic acid water, or of mixtures of sesqui-carbonate of soda, and tartaric acid. The bread proved doughy and dense in every case, though le so with the latter mixture than the former. No loaf bread can, indeed, be well made by any of these two extemporaneous systems, because they are inconsistent with the thorough kneading of the dough. It is this proce which renders dough at once elastic enough to expand when carbonic acid gas is generated within it, and cohesive enough to confine the gas when it is generated. The whole gas of the loaf is disengaged in its interior by a continuous fermentation, after all the proce es of kneading have been finished; for the loaf, after being kneaded, weighed out, and shaped, is set aside till it expands gradually to double its bulk, before it is put into the oven. But when a dough containing sesqui-carbonate of soda is mixed with one containing muriatic acid, in due proportions to form the just dose of culinary salt, the gas escapes during the nece ary incorporation of the two, and the bread formed from it is dense and hard. Dr. Whiting has, however, made this old chemical proce the subject of a new patent for baking bread. [10] Treatise on the Art of Bread Making, p. 56. When the baker prepares his dough, he takes a portion of the water needed for the batch, having raised its temperature to from 70° to 100° F., di olves a certain proportion of his salt in it, then adds the yeast, and a certain quantity of his flour. This mixture, called the sponge , is next covered up in the small kneading-trough, alongside of the large one, and let alone for setting in a warm situation. In about an hour, signs of vinous fermentation appear, by the swelling and heaving up of the sponge, in consequence of the generation of carbonic acid; and if it be of a semi-liquid consistence, large air bubbles will force their way to the surface, break, and disappear in rapid succe ion. But when the sponge has the consistence of thin dough , it confines the gas, becomes thereby equably and progre ively inflated to double its original volume; when no longer capable of containing the pent-up air, it bursts and subsides. This proce of rising and falling alternately might be carried on during twenty-four hours, but the baker has learned by experience to guard against allowing full scope to the fermentative principle. He generally interferes after the first, or at furthest after the second or third dropping of the sponge; for were he not to do so, the bread formed with such dough would invariably be found sour to the taste and the smell. Therefore he adds at this stage to the sponge the reserved proportions of flour, salt, and water, which are requisite to make the dough of the desired consistence and size; and next incorporates the whole together by a long and laborious course of kneading. When this operation has been continued till the fermenting and the fresh dough have been intimately blended, and till the glutinous matter of both is worked into such union and consistence that the ma becomes so tough and elastic as to receive the smart pre ure of the hand without adhering to it, the kneading is suspended for some time. The dough is now abandoned to itself for a few hours, during which it continues in a state of active fermentation throughout its entire ma . Then it is subjected to a second but much le laborious kneading, in order to distribute the generated gas as evenly as po ible among its parts, so that they may all partake equally of the vesicular structure. After this second kneading, the dough is weighed out into the portions suitable to the size of bread desired; which are of course shaped into the proper forms, and once more set aside in a warm situation. The continuance of the fermentation soon disengages a fresh quantity of carbonic acid gas, and expands the lumps to about double their pristine volume. These are now ready for the oven, and when they finally quit it in the baked state, are about twice the size they were when they went in. The generation of the due quantity of gas should be complete before the lumps are transferred to the oven; because whenever they encounter its heat, the proce of fermentation is arrested; for it is only the previously existing air which gets expanded throughout every part of the loaf, swells out its volume, and gives it the piled and vesicular texture. Thus the well-baked loaf is composed of an infinite number of cellules filled with carbonic acid gas, and apparently lined with a glutinous membrane of a silky softne . It is this which gives the light, elastic porous constitution to bread. After suffering the fermentative proce to exhaust itself in a ma of dough, and the dough to be brought into that state in which the addition of neither yeast, nor starch, nor gluten will produce any effect in restoring that action, if we mix in 4 per cent. of saccharine matter, of any kind, with a little yeast, the proce of fermentation will immediately re-commence, and pursue a course as active and lengthened as at first, and cease about the same period. [11] [11] Dr. Colquhoun, in Annals of Philosophy for 1826, vol. xii. p. 171. This experiment, taken in connection with the facts formerly stated, proves that what was called panary fermentation, is nothing but the ancient and well-known proce of the vinous fermentation of sugar, which generates alcohol. There seems to be but one objection to the adoption of this theory. After the loaf is baked, there is found in its composition nearly as much saccharine matter as existed in the flour before fermentation. M. Vogel states that in the baked bread there remains 3·6 parts of sugar, out of the 5 parts which it originally contained. Thus, in 100 parts of loaf bread prepared with wheaten flour, distilled water, and yeast without the admixture of any common salt, he found the following ingredients :— | Sugar | 8· | 6 | | | Torrefied or gummy starch | 18· | 0 | | Starch | 53· | 5 | | Gluten, combined with a little starch, | 20· | 75 | | Exclusive of carbonic acid, muriate of lime, phosphate of lime, . | It must be borne in mind that in every loaf the proce of fermentation has been prematurely checked by the baker’s oven, and therefore the saccharine constituent can never be wholly decomposed. It seems certain, also, that by the action of gluten upon the starch in the early stage of the firing, a quantity of sugar will be formed by the saccharine fermentation; which we have explained in treating of Beer . Several ma es of dough were prepared by Dr. Colquhoun in which pure wheat starch was mixed with common flour, in various proportions. In some of the lumps this starch had been gelatinized, with the minimum of hot water, before it was added to the flour. After introducing the usual dose of salt, the dough was thoroughly kneaded, set apart for the proper period, allowed to ferment in the accustomed way, and then baked in the oven. In outward appearance, increase of bulk, and vesicular texture, none of them differed materially from a common loaf, baked along with them for the sake of comparison; except that when the starch considerably exceeded the proportion of flour in the lump, the loaf, though whiter, had not risen so well, being somewhat le vesicular. But, on tasting the bread of each loaf, those which contained most gelatinized starch were unexpectedly found to be the sweetest. The other loaves, into which smaller quantities of the gelatinized starch had been introduced, or only some dry starch, had no sweetish taste whatever to distinguish them from ordinary bread. These facts seem to establish the conclusion, that the presence of gelatinous starch in bread put into the oven, is a means of forming a certain portion of saccharine matter within the loaf, during the baking proce . Now it is more than probable that gelatinized starch does exist, more or le , in all loaves which have been fermented by our usual methods, and hence a certain quantity of sugar will nece arily be generated at its expense, by the action of heat. Thus the difficulty started by M. Vogel is sufficiently solved; and there remains no doubt that, in the saccharine principle of flour, the fermentation has its origin and end, while dough is under fermentation. The source of the sourne which supervenes in bread, under carele or unskilful hands, had been formerly ascribed to each of all the constituents of flour; to its gluten, its starch, and its sugar; but erroneously, as we now see: for it is merely the result of the second fermentation which always succeeds the vinous, when pushed improperly too far. It has been universally taken for granted by authors, that the acid thus generated in dough is the acetic. But there appear good grounds to believe that it is frequently a le volatile acid, probably the lactic, particularly when the proce has been tardy, from the imperfection of the yeast or the bad quality of the flour. The experiments of Vogel, Bra con not, and others, prove that the latter acid is generated very readily, and in considerable quantity during the spontaneous decomposition of a great many vegetable substances, when in a state of humidity. The presence of lactic acid would account for the curious fact, that the acidity of unbaked dough is much more perceptible to the taste than to the smell; while the sourne of the same piece of bread, after coming out of the oven, is, on the contrary, much more obvious to the olfactory organs than to the palate. But this is exactly what ought to happen, if the lactic acid contributes, in conjunction with the acetic, to produce the acescence of the dough. At the ordinary temperature of a bakehouse, the former acid, though very perceptible in the mouth, is not distinguishable by the nostrils; but as it is easily decomposed by heat, no sooner is it exposed to the high temperature of the oven, than it is resolved, in a great measure, into acetic acid [12] , and thus becomes more manifest to the sense of smell, and le to that of taste. This theory seems to explain satisfactorily all the phenomena accompanying the progre of fermentation in baker’s dough, and also some of its results in the proce of baking which do not easily admit of any other solution. [12] Berzelius. There are extremely simple and effectual methods for enabling the baker to adopt measures either to prevent or correct the evil of acescence, and these are to neutralize the acid by the due exhibition of an alkali, such as soda; or an alkaline earth, such as magnesia or chalk. And it affords a striking proof of how much the artisan has been accustomed to plod, uninquiring and uninformed, over the same ground, that a remedy so safe and so economical, should remain at this day unthought of and unemployed by most of the manufacturers of bread in the United Kingdom. The introduction of a small portion of carbonate of soda will rectify any occasional error in the result of the so called panary fermentation, and will, in fact, restore the dough to its pristine sweetne . The quantity of acetate of soda, which will be thus present in the bread, will be altogether inconsiderable; and as it has no disagreeable taste, and is merely aperient to the bowels in a very mild degree, it can form no objection in the eye of the public police. The restoration of dough thus tainted with acid, and its conversion into pleasant and wholesome bread, has been sufficiently verified by experiment. But, according to Mr. Edmund Davy, carbonate of magnesia may be used with still greater advantage, as during the slow action of the acid upon it, the carbonic acid evolved serves to open up and lighten bread which would otherwise be dense and doughy from the indifferent quality of the flour. Here, however, the dangerous temptation lies with a sordid baker to use cheap or damaged flour, and to rectify the bread made of it by chemical agents, innocent in themselves, but injurious as masks of a bad raw material. When sour yeast must be used, as sometimes happens with the country bakers, or in private houses at a distance from beer breweries, there can be no harm, but, on the contrary, much propriety, in correcting its acidity, by the addition of as much carbonate of soda to it as will effect its neutralization, but nothing more. When sour yeast has been thus corrected, it has been found, in practice, to po e its fermentative power unimpaired, and to be equally efficacious, with fresh formed yeast, in making good palatable loaves. We have seen that, in baking, about one fourth of the starch is converted into a matter po e ing the properties of British gum (see Starch ), and also that the gluten, though not decomposed, has its particles disunited, and is not so tough and adhesive as it is in the flour. This principle is also, as we have said, useful in cementing all the particles of the dough into a tenacious ma , capable of confining the elastic fluid generated by the vinous fermentation of the sugar. Starch is the main constituent, the basis of nourishment in bread, as well as in all farinaceous articles of food. The albumen also of the wheat being coagulated by the heat of the oven, contributes to the setting of the bread into a consistent elastic body. In the mills in the neighbourhood of London, no le than seven distinct sorts of flour are ground out of one quantity of wheat. These are for one quarter — | Fine flour | 5 | bushels | 3 | | pecks. | | Seconds | 0 | | 2 | | | Fine middlings | 0 | | 1 | | | Coarse middlings | 0 | | 0 | ·5 | | | Bran | 3 | | 0 | | | Twenty-penny | 3 | | 0 | | | Pollard | 2 | | | | 14 | | 2 | ·5 | | So that we have nearly a double bulk of flour, or 14 bushels and 2 1 ⁄ 2 pecks from 8 bushels of wheat. In the sifting of the flour through the bolter, there is a fine white angular meal obtained called sharps, which forms the central part of the grain. It is consumed partly by the fine biscuit bakers. The bakers of this country were formerly bound by law to bake three kinds of bread, the wheaten , standard wheaten , and the household ; marked respectively with a W, S W, and H, and if they omitted to make these marks on their bread they were liable to a penalty. The size of the loaves were usually peck, half-peck, quartern, and half-quartern; the weights of which, within 48 hours of their being baked, should have been respectively 17 lbs. 6 oz.; 8 lbs. 11 oz.; 4 lbs. 5 oz. 8 dr.; and 4 lbs. 2 oz. 14 dr. In general they weigh about one-seventh more before they enter the oven, or they lose one-seventh of their weight in baking. The French bread loses fully one-sixth in the oven, owing chiefly to its more oblong thin shape, as compared to the cubical shape of the English bread. But this lo of weight is very variable, being dependent upon the quality of the wheaten flour, and the circumstances of baking. The present law in England defines the quartern loaf at 4 lbs., and subjects the baker to a penalty if the bread be one ounce lighter than the standard. Hence it leaves the baker in self-defence, to leave it in rather a damp and doughy state. But there is much light bread sold in London. I have met with quartern loaves of 3 lbs. 10 ozs. A sack of flour weighing 280 lbs. was presumed by the framers of our former parliamentary acts, for the a ize of bread, to be capable of being baked into 80 loaves. If this proportion had been correct, one-fifth part of our quartern loaf must consist of water and salt, and four-fifths of flour. But in general, of good wheaten flour, three parts will take up one part of water; so that the sack of flour should have turned out, and actually did turn out, more than 80 loaves. At present with 4 lb. bread it may well yield 92 loaves. The following statement of the system of baking at Paris, I received in 1835 from a very competent judge of the busine . 1,000 kilogrammes of wheat = 5 quarters English, cost 200 fr., and yield 800 kilos of flour of the best white quality, equivalent to 5 1 ⁄ 10 sacks French. Hence the sack of flour costs 40 francs at the mill, and including the carriage to Paris, it costs 45 or 46 francs. The profit of the flour dealer is about 3 1 ⁄ 2 francs, and the sale price becomes from 43 to 50 francs. | Bread manufactured from the above. | | £ | s. | d. | | £ | s. | d. | | One day’s work of an ordinary baker, who makes four batches in a day, consists of 3 sacks at 50 francs, or 2 l. sterling each | | 6 | 0 | 0 | | | Salt 23⁄4 lbs. at 2 d. per lb. | | 0 | 0 | 5 | 1⁄2 | | Yeast or leaven 3 lbs. at 5 d. | | 0 | 1 | 3 | | | Total cost of materials | | 6 | 1 | 8 | 1⁄2 | | Expenses of Baking. | | Three workmen at different rates of wages, 15 francs | 0 | 12 | 0 | | | Fire-wood 0, as the charcoal produced pays for it | | General expenses, such as rent, taxes, interest of capital, . | 0 | 12 | 0 | | | 1 | 4 | 0 | = | 1 | 4 | 0 | | | 7 | 5 | 8 | 1⁄2 | | For this sum 315 loaves are made, being 105 for every sack of flour weighing 156·66 kilos, or 3442⁄3 lbs. avoird. One loaf contains therefore 344·65 105 = 3·282 lbs., and as 100 lbs. of flour in Paris i an baking are reckoned to produce 127 lbs. of bread, each loaf will weigh 4·168 lbs., avoird., and will cost 7 l. 5 s. 81⁄2 d. divided by 315 = 51⁄2 d. very nearly. The value of 315 loaves at the sale price of 6 d. will be | | 7 | 17 | 6 | | | Upon this day’s work the clear profit is therefore | | 0 | 11 | 9 | 1⁄2 | A new baking establishment has been recently formed at the Royal Clarence Victualling Establishment at Weevil, near Portsmouth, upon a scale of magnitude nearly sufficient to supply the whole royal navy with biscuits, and that of a very superior description. The following account of it is taken from the United Service Journal. “It having been discovered that the flour supplied to government by contract, had in many instances been most shamefully adulterated, the corn is ground at mills comprised within the establishment, by which means the introduction of improper ingredients is prevented, and precisely the proportion of bran which is requisite in the composition of good sea-biscuit is retained, and no more. The flour-mill is furnished with 10 pairs of stones, by which 40 bushels of flour may be ground and dre ed ready for baking, in an hour. The baking establishment consists of 9 ovens, each 13 feet long by 11 feet wide, and 17 1 ⁄ 2 inches in height. These are each heated by separate furnaces, so constructed that a blast of hot air and fire sweeps through them, and gives to the interior the requisite dose of heat in an incredible short space of time. The first operation in making the biscuits, consists in mixing the flour or rather meal and water; 13 gallons of water are first introduced into a trough, and then a sack of the meal, weighing 280 lbs. When the whole has been poured in by a channel communicating with an upper room, a bell rings, and the trough is closed. An apparatus consisting of two sets of what are called knives, each set ten in number, are then made to revolve amongst the flour and water by means of machinery. This mixing operation lasts one minute and a half, during which time the double set of knives or stirrers makes twenty-six revolutions. The next proce is to cast the lumps of dough under what are called the breaking-rollers,—huge cylinders of iron, weighing 14 cwt. each, and moved horizontally by the machinery along stout tables. The dough is thus formed into large rude ma es 6 feet long by 3 feet broad, and several inches thick. At this stage of the busine , the kneading is still very imperfect, and traces of dry flour may still be detected. These great ma es of dough are now drawn out, and cut into a number of smaller ma es about a foot and a half long by a foot wide, and again thrust under the rollers, which is repeated until the mixture is so complete that not the slightest trace of any inequality is discoverable in any part of the ma . It should have been stated that two workmen stand one at each side of the rollers, and as the dough is flattened out, they fold it up, or double one part upon another, so that the roller at its next pa age squeezes these parts together, and forces them to mix. The dough is next cut into small portions, and being placed upon large flat boards, is, by the agency of machinery, conveyed from the centre to the extremity of the baking-room. Here it is received by a workman, who places it under what is called the sheet roller, but which, for size, colour, and thickne , more nearly resembles a blanket. The kneading is thus complete, and the dough only requires to be cut into biscuits before it is committed to the oven. The cutting is effected by what is called the cutting-plate, consisting of a net-work of 52 sharp-edged hexagonal frames, each as large as a biscuit. This frame is moved slowly up and down by machinery, and the workman, watching his opportunity, slides under it the above-described blanket of dough, which is about the size of a leaf of a dining table; and the cutting-frame in its descent indents the sheet, but does not actually cut it through, but leaves sufficient substance to enable the workman at the mouth of the oven to jerk the whole ma of biscuits unbroken into it. The dough is prevented sticking to the cutting-frame by the following ingenious device: between each of the cutter-frames is a small flat open frame, movable up and down, and loaded with an iron ball, weighing several ounces. When the great frame comes down upon the dough, and cuts out 52 biscuits, each of these minor frames yields to the pre ure, and is raised up; but as soon as the great frame rises, the weight of the balls acting upon the little frames, thrusts the whole blanket off, and allows the workmen to pull it out. One quarter of an hour is sufficient to bake the biscuit, which is afterwards placed for three days in a drying room, heated to 85° or 90°, which completes the proce .” The following statement of the performance of the machinery is taken from actual experiment; in 116 days, during 68 of which, the work was continued for only 7 1 ⁄ 2 hours; and during 48, for only 5 3 ⁄ 4 hours each day, in all 769 working hours, equal to 77 days of 10 hours each; the following quantity of biscuit was baked in the 9 ovens; viz., 12,307 cwt. = 1,378,400 lbs. The wages of the men employed in baking this quantity amounted to 273 l. 10 s. 9 1 ⁄ 2 d. ; if it had been made by hand, the wages would have been 933 l. 9 s. 10 d. ; saving in the wages of labour, 659 l. 7 s. 0 1 ⁄ 2 d. In this, is not included any part of the interest of the sum laid out upon the machine, or expended in keeping it in order. But in a very few years at such an immense rate of saving, the cost of the engine and other machinery will be repaid. This admirable apparatus is the invention of T. T. Grant, Esq. storekeeper of the Royal Clarence Victualling Establishment, who, we believe, has been properly rewarded, by a grant of 2,000 l. from government. The labour of incorporating the ingredients of bread, viz. flour, water and salt, or kneading dough, is so great as to have led to the contrivance of various mechanical modes of producing the same effect. One of the most ingenious is that for which a patent was obtained in August, 1830, by Mr. Edwin Clayton. It consists of a rotatory kneading trough, or rather barrel, mounted in bearings with a hollow axle, and of an interior frame of cast iron made to revolve by a solid axle which pa es through the hollow one; in the frame there are cutters diagonally placed for kneading the dough. The revolving frame and its barrel are made to turn in contrary directions, so as greatly to save time and equalize the operation. This double action represents kneading by the two hands, in which the dough is inverted from time to time, torn asunder, and reunited in every different form. The mechanism will be readily understood from the following description. IMG:4147767755307473660_illo0180.png:Dough kneader Fig. 169. exhibits a front elevation of a rotatory kneading trough, constructed according to improvements specified by the patentee, the barrel being shown in section: a is the barrel, into which the several ingredients, consisting of flour, water, and yeast, are put, which barrel is mounted in the frame-work b , with hollow axles c and d , which hollow axles turn in suitable bearings at e ; f is the revolving frame which is mounted in the interior of the barrel a , by axles g and h . The ends of this revolving frame are fastened, or braced together by means of the oblique cutters or braces i , which act upon the dough when the machine is put in motion, and thus cause the operation of kneading. Either the barrel may be made to revolve without the rotatory frame, or the rotatory frame without the barrel, or both may be made to revolve together, but in opposite ways. These several motions may be obtained by means of the geer-work, shown at k , l , and m , as will be presently described. If it be desired to have the revolving motion of the barrel and rotatory frame together, but in contrary directions, that motion may be obtained by fastening the hollow axle of the wheel m , by means of a screw n , to the axle h , of the rotatory frame f , tight, so as they will revolve together, the other wheels k and l being used for the purpose of reversing the motion of the barrel. It will then be found that by turning the handle o , the two motions will be obtained. If it be desired to put the rotatory frame f , only into motion, that action will be obtained by loosening the screw n , upon the axle of the wheel m , when it will be found that the axle h , will be made to revolve freely by means of the winch o , without giving motion to the wheels k , l , and m , and thus the barrel will remain stationary. If the rotatory action of the barrel be wanted, it will be obtained by turning the handle p , at the reverse end of the machine, which, although it puts the geer at the opposite end of the barrel into motion, yet as the hollow axle of the wheel m is not fastened to the axle h , by the screw n , these wheels will revolve without carrying round the frame f . M. Kuhlmann, Profe or of Chemistry at Lille, having been called upon several times by the courts of justice to examine by chemical proce es bread suspected of containing substances injurious to health, collected some interesting facts upon the subject, which were published under the direction of the central council of salubrity of the department du Nord . For some time public attention had been drawn to an odious fraud committed by a great many bakers in the north of France and in Belgium,—the introduction of a certain quantity of sulphate of copper into their bread. When the flour was made from bad grain this adulteration was very generally practised, as was proved by many convictions and confe ions of the guilty persons. When the dough does not rise well in the fermentation ( le pain pou e plat ), this inconvenience was found to be obviated by the addition of blue vitriol, which was supposed also to cause the flour to retain more water. The quantity of blue water added is extremely small, and it is never done in presence of strangers, because it is reckoned a valuable secret. It occasions no economy of yeast, but rather the reverse. In a litre (about a quart) of water, an ounce of sulphate of copper is di olved; and of this solution a wine-gla full is mixed with the water nece ary for 50 quartern or 4 pound loaves. M. Kuhlmann justly observes that there can be no safety whatever to the public when such a practice is permitted, because ignorance and avarice are always apt to increase the quantity of the poisonous water. In analyses made by him and his colleagues, portions of bread were several times found so impregnated with the above salt that they had acquired a blue colour, and presented occasionally even small crystals of the sulphate. By acting on the poisoned bread with distilled water and testing the water with ferro-cyanate (pru iate) of potash, the reddish brown precipitate or tint characteristic of copper will appear even with small quantities. Should the noxious impregnation be still more minute, the bread should be treated with a very dilute nitric-acid, either directly, or after incineration in a platinum capsule, and the solution, when concentrated by evaporation, should be tested by the ferro-cyanate of potash. In this way, a one seventy thousandth part of sulphate of copper may be detected. M. Kuhlmann deduces, from a series of experiments on baking with various small quantities of sulphate of copper, that this salt exercises an extremely energetic action upon the fermentation and rising of the dough, even when not above one seventy thousandth part of the weight of the bread is employed; or one grain of sulphate for ten pounds of bread. The proportion of the salt which makes the bread rise best is one twenty thousandth, or one grain in three pounds of bread. If much more of the sulphate be added, the bread becomes moist, le white, and acquires a peculiar disagreeable smell like that of leaven. The increase of weight by increased moisture may amount to one sixteenth without the bread appearing softer, in consequence of the solidifying quality of the copper; for the acid does not seem to have any influence; as neither sulphate of soda, sulphate of iron, nor sulphuric acid have any analogous power. Alum operates like blue vitriol on bread, but larger quantities of it are required. It keeps water , and raises well , to use the bakers’ terms. When alum is present in bread it may be detected by treating the bread with distilled water, filtering the water first through calico, and next through filtering paper, till it becomes clear; then dividing it into two portions, and into the one pouring a few drops of nitrate or muriate of barytes, and into the other a few drops of water of ammonia. In the former a heavy white precipitate indicating sulphuric acid will appear, and in the latter a light precipitate of alumina, red is soluble by a few drops of solution of caustic potash. When chalk or Paris plaster is used to sophisticate flour, they may be best detected by incinerating the bread made of it, and examining the ashes with nitric acid which will di olve the chalk with effervescence, and the Paris plaster without. In both cases the calcareous matter may be demonstrated in the solution, by oxalic acid, or better by oxalate of ammonia. In baking puff-paste the dough is first kneaded along with a certain quantity of butter, then rolled out into a thin layer, which is coated over with butter, and folded face-wise many times together, the upper and under surfaces being made to correspond. This stratified ma is again rolled out into a thin layer, its surface is besmeared with butter, and then it is folded face-wise as before. When this proce is repeated ten or a dozen times, the dough will consist of many hundred parallel lam inæ, with butter interposed between each pair of plates. When a moderately thick ma of this is put into the oven, the elastic vapour disengaged from the water and the butter, diffuses itself between each of the thin lam inæ, and causes them to swell into what is properly called puff-paste, being an a emblage of thin membranes, each dense in itself, but more or le distinct from the other, and therefore forming apparently but not really light bread. One of the most curious branches of the baker’s craft is the manufacture of gingerbread, which contains such a proportion of mola es, that it cannot be fermented by means of yeast. Its ingredients are flour, mola es or treacle, butter, common potashes, and alum. After the butter is melted, and the potashes and alum are di olved in a little hot water, these three ingredients, along with the treacle, are poured among the flour, which is to form the body of the bread. The whole is then incorporated by mixture and kneading into a stiff dough. Of these five constituents the alum is thought to be the least e ential, although it makes the bread lighter and crisper, and renders the proce more rapid; for gingerbread dough requires to stand over several days, sometimes 8 or 10, before it acquires that state of porosity which qualifies it for the oven. The action of the treacle and alum on the potashes in evolving carbonic acid, seems to be the gasefying principle of gingerbread; for if the carbonate of potash is withheld from the mixture, the bread, when baked, resembles in hardne a piece of wood. Treacle is always acidulous. Carbonate of magnesia and soda may be used as substitutes for the potashes. Dr. Colquhoun has found that carbonate of magnesia and tartaric acid may replace the potashes and the alum with great advantage, affording a gingerbread fully more agreeable to the taste, and much more wholesome than the common kind, which contains a notable quantity of potashes. His proportions are one pound of flour, a quarter of an ounce of carbonate of magnesia, and one eighth of an ounce of tartaric acid; in addition to the treacle, butter, and aromatics as at present used. The acid and alkaline earth must be well diffused through the whole dough. The magnesia should, in fact, be first of all mixed with the flour. Pour the melted butter, the treacle, and the acid di olved in a little water all at once among the flour, and knead into a consistent dough, which being set aside for half an hour or an hour will be ready for the oven, and should never be kept unbaked more than 2 or 3 hours. The following more complete recipe is given by Dr. Colquhoun, for making thin gingerbread cakes :— | Flour | 1 | | lb. | | | Treacle | 0 | 1⁄2 | | Raw sugar | 0 | 1⁄4 | | | Butter | 2 | | oz. | | Carbon. magnesia | 0 | 1⁄4 | | | Tartaric acid | 0 | 1⁄8 | | | Ginger | 0 | 1⁄8 | | | Cinnamon | 0 | 1⁄8 | | | Nutmeg | 1 | | | | This compound has rather more butter than common thin gingerbread. | I shall here insert a pa age from my Dictionary of Chemistry as published in 1821; as it may prove interesting to many of my present readers. “Under Proce of Baking , in the Supplement to the Encyclopedia Britannica, we have the following statement:—‘An ounce of alum is then di olved over the fire in a tin pot, and the solution poured into a large tub, called by the bakers the seasoning-tub. Four pounds and a half of salt are likewise put into the tub, and a pailful of hot water.’— Foot note on this pa age. —‘In London, where the goodne of bread is estimated entirely by its whitene , it is usual with those bakers who employ flour of an inferior quality, to add as much alum as common salt to the dough; or, in other words, the quantity of salt added is diminished one half, and the deficiency supplied by an equal weight of alum. This improves the look of the bread very much, rendering it much whiter and firmer.’” In a pa age which we shall presently quote, our author represents the bakers of London in a conspiracy to supply the citizens with bad bread. We may hence infer that the full allowance he a igns of 2 1 ⁄ 4 pounds of alum for every 2 1 ⁄ 4 pounds of salt, will be adopted in converting the sack of flour into loaves. But as a sack of flour weighs 280 pounds, and furnishes on an average 80 quartern loaves, we have 2 1 ⁄ 4 pounds divided by 80, or 15750 grains 80 = 197 grains, for the quantity present, by this writer, in a London quartern loaf. Yet in the very same page (39th of vol. ii.) we have the following pa age: “Alum is not added by all bakers. The writer of this article has been a ured by several bakers of respectability, both in Edinburgh and Glasgow, on whose testimony he relies, and who made excellent bread, that they never employed any alum. The reason for adding it given by the London bakers is, that it renders the bread whiter, and enables them to separate readily the loaves from each other. This addition has been alleged by medical men, and is considered by the community at large, as injurious to the health, by occasioning constipation. But if we consider the small quantity of this salt added by the baker, not quite 5 1 ⁄ 2 grains to a quartern loaf, we will not readily admit these allegations. Suppose an individual to eat the seventh part of a quartern loaf a day, he would only swallow eight-tenths of a grain of alum, or, in reality, not quite so much as half a grain; for one half of this salt consists of water. It seems absurd to suppose that half a grain of alum, swallowed at different times during the course of a day, should occasion constipation.” Is it not more absurd to state 2 1 ⁄ 4 pounds or 36 ounces, as the alum adulteration of a sack of flour by the London bakers, and within a few periods to reduce the adulteration to one ounce? That this voluntary abstraction of 35 ⁄ 36 of the alum, and substitution of superior and more expensive flour is not expected by him from the London bakers, is sufficiently evident from the following story. It would appear that one of his friends had invented a new yeast for fermenting dough, by mixing a quart of beer barm with a paste made of ten pounds of flour and two gallons of boiling water, and keeping this mixture warm for six or eight hours. “Yeast made in this way,” says he, “answers the purposes of the baker much better than brewers’ yeast, because it is clearer, and free from the hop mixture which sometimes injures the yeast of the brewer. Some years ago the bakers of London, sensible of the superiority of this artificial yeast, invited a company of manufacturers from Glasgow to establish a manufactory of it in London, and promised to use no other. About 5,000 l. accordingly was laid out on buildings and materials, and the manufactory was begun on a considerable scale. The ale-brewers, finding their yeast, for which they had drawn a good price, lie heavy on their hands, invited all the journeymen bakers to their cellars, gave them their full of ale, and promised to regale them in that manner every day, provided they would force their masters to take all their yeast from the ale-brewers. The journeymen accordingly declared, in a body, that they would work no more for their masters unle they gave up taking any more yeast from the manufactory. The masters were obliged to comply; the new manufactory was stopped, and the inhabitants of London were obliged to continue to eat worse bread, because it was the interest of the ale-brewers to sell the yeast. Such is the influence of journeymen bakers in the metropolis of England!” This doleful diatribe seems rather extravagant; for surely beer yeast can derive nothing noxious to a porter drinking people, from a slight impregnation of hops; while it must form probably a more energetic ferment than the fermented paste of the new company, which at any rate could be prepared in six or eight hours by any baker who found it to answer his purpose of making a pleasant-eating bread. But it is a very serious thing for a lady or gentleman of sedentary habits, or infirm constitution, to have their digestive proce daily vitiated by damaged flour, whitened with 197 grains of alum per quartern loaf. Acidity of stomach, indigestion, flatulence, headaches, palpitation, costivene , and urinary calculi may be the probable consequences of the habitual introduction of so much acidulous and acescent matter. I have made many experiments upon bread, and have found the proportion of alum very variable. Its quantity seems to be proportional to the badne of the flour; and hence when the best flour is used, no alum need be introduced. That alum is not nece ary for giving bread its utmost beauty, spongine , and agreeablene of taste, is undoubted; since the bread baked at a very extensive establishment in Glasgow, in which about 20 tons of flour were regularly converted into loaves in the course of a week, united every quality of appearance with an absolute freedom from that acido-astringent drug. Six pounds of salt were used for every sack of flour; which, from its good quality, generally afforded 83 or 84 quartern loaves of the legal weight of four pounds five ounces and a half each. The loaves lost nine ounces in the oven. Every baker ought to be able to analyse his flour. He may proceed as follows:—A ductile paste is to be made with a pound of the flour and a sufficient quantity of water, and left at rest for an hour; then having tied acro a bowl a piece of silken sieve-stuff, a little below the surface of the water in the bowl, the paste is to be laid upon the sieve on a level with the water, and kneaded tenderly with the hand, so as merely to wash the starchy particles out of it. This portion of the flour gets immediately diffused through the water, some of the other constituents di olve, and the gluten alone remains upon the filter. The water must be several times renewed till it ceases to become milky. The last washings of the gluten are made out of the sieve. The whole of the turbid washings are to be put into a tall conical gla or stoneware ve el, and allowed to remain at rest, in a cool place, till they deposit the starch. The clear supernatant liquor is then decanted off. The deposit consists of starch, with a little gluten. It must be washed till the water settles over it quite clear, and then it is to be dried. The filtered waters being evaporated, at a boiling heat, discover flocks floating through them, which have been supposed by some to be albumen, and by others gluten. At last, phosphate of lime precipitates. When the residuum has a umed a syrupy consistence in the cold, it is to be mixed with alcohol, in order to di olve out its sugar. Cold water being added to what remains, effects a solution of the mucilage, and leaves the insoluble azotized matter with the phosphate of lime. By this mode of analysis a minute portion of resin may remain in the gluten and in the washing water; the gluten retains also a small proportion of a fixed oil, and a volatile principle, which may be removed by alcohol. If we wish to procure the resin alone, we must first of all treat the flour, well dried, with alcohol. When corn flour, poor in gluten, is to be analyzed, the dough must be inclosed in a linen bag, kneaded with water, and washed in that state. In analyzing barley-meal by the above proce , hordeine , mixed with common starch, is obtained: they may be separated by boiling water, which di olves the starch, and leaves the hordeine under the aspect of saw-dust. IMG:4147767755307473660_illo0183.png:Oven Fig. 171. is the plan of a London baker’s oven, fired with coal fuel. Fig. 170. is the longitudinal section. a , the body of the oven; b , the door; c , the fire-grate and furnace; d , the smoke flue; e , the flue above the door, to carry off the steam and hot air, when taking out the bread; f , rece below the door, for receiving the dust; g , damper plate to shut off the steam flue; h , damper plate to shut off smoke flue, after the oven has come to its proper heat; i , a small iron pan over the fire-place c , for heating water; k , ash-pit below the furnace. IMG:4147767755307473660_illo0184.png:Oven Fig. 172. is the front view; the same letters refer to the same objects in all the figures. The flame and burnt air of the fire at c , sweep along the bottom of the oven by the right hand side, are reflected from the back to the left hand side, and thence escape by the flue d ; (see plan fig. 171 ). Whenever the oven has acquired the proper degree of heat, the fire is withdrawn, the flues are closed by the damper plates, and the lumps of fermented dough are introduced.