صور الصفحة
PDF
[graphic]

CYCLOPEDIA OF USEFUL ARTS,

J&rjjnmfltl unit Cjjtnriral,

MANUFACTURES, MINING AND ENGINEERING.

ABATTOIR (from the French verb abattre, to fell or knock down), a term applied to an establishment situated on the outskirts of a large town, where animals are slaughtered for supplying the inhabitants with meat. In ancient Rome, a corporation of butchers had the privilege of supplying the city with meat. These butchers, who were for a long period scattered over different parts of the city, were at length collected into a single quarter. In the reign of the Emperor Nero, the grand market, with its slaughter-houses, formed a magnificent establishment, which has been recorded to posterity in a medal. In Paris, from time immemorial, a corporation of butchers had the privilege of purehasing cattle and supplying the city with meat; but here the policy of the Romans ceased to be imitated, for the cattle, purehased at the markets of Sceaux or Poissy, were driven through the public streets to the butchers' shops, before which they were slaughtered and prepared for sale, the refuse

animal matters being stored in large tubs; the whole arrangement being as dangerous to the persons and health of the inhabitants as it was offensive to the sight. Many of the objections which applied to Paris, still apply to London and other large towns of England.

A remedy for these evils had long engaged the attention of the French government. The butchers themselves were most energetic in opposing a change; but at length the strong hand of the Emperor Napoleon put down all opposition, and, by a decree dated 9th February, 1810, it was ordered, that five abattoirs should be erected in the neighbourhood of Paris at the expense of the city, under the direction of a Committee of Arehitects and Engineers appointed for the purpose. Plans were accordingly prepared with the assistance and advice of a retired master butcher. Eight years were occupied in carrying them into execution, and they were opened for public use in 1818.

The five abattoirs of Paris are those of Roule, and

[graphic][merged small][ocr errors]

Villejuif, each provided with thirty-two slaughterhouses; Grenelle containing forty-eight, and Menilmontant and Montmartre, each containing sixty-four slaughter-houses, making altogether 240 slaughterhouses. This is less than the number of butehers in Paris; but as some butehers contract with others for having their cattle slaughtered and prepared for sale, and as in some cases one slaughter-house is shared by two or three butehers, whose respective trades are but small, the number of slaughter-houses has hitherto been found sufficient. When the meat has been properly prepared for sale at the abattoirs, it is removed in carts to the various markets and butehers' shops of the city.

By these arrangements, not ouly is the city freed from a disgusting and even dangerous occupation, but additional facilities are afforded for inspection. As all the cattle slaughtered for the supply of Paris must be driven into the abattoirs, the inspectors can easily ascertain whether the animals are healthy, and in a fit state to furnish food to human beings. Besides this,

all the offal and refuse animal matters can be easily collected together, for supplying various trades which are dependent on the slaughter-houses, such as the manufacturers of glue, of gelatine, of Prussian blue, of hoof-oil, of blood-manure, &c., whose works are collected near the abattoirs, and thus relieve the city of trades which are as offensive, or even more so than the occupation of the slaughterer.

A very favourable idea of these establishments will be conveyed by the accompanying view of the abattoir of Roule. (Fig. 1.) As the original site of this abattoir was on sloping ground, the earth excavated during the process of levelling was formed into an esplanade before the entrance. Plantations were here formed, and a beautiful avenue of trees thus separates this abattoir from surrounding buildings. At the upper part of the slope the earth is supported by arches, the vaults of which serve as coach-houses and stables, and above is a spacious terrace also planted with trees. Fig. 2 is a ground plan of this abattoir, which may be taken as the

[merged small][ocr errors][ocr errors][ocr errors][graphic][ocr errors][ocr errors][ocr errors][ocr errors][ocr errors]
[merged small][graphic][merged small]

the sheep and calves. There are racks and bins for fodder, and a large water-trough. The upper stories of these buildings are divided into small rooms, which are used as granaries, one of which is appropriated to each buteher. D D are ranges of slaughter-houses separated from each other by a court-yard. Each slaughter-house is about 16£ feet wide by 32f feet long, and is furnished with two entrances, one by which the animals are introduced, and the other, on the external front, for removing the carcases. There is also a cock for supplying the water required in washing, a channel sunk below the paved floor, a windlass and a pulley for drawing up the carcass to be flayed, and a couple of poles fixed into the wall at one end, seven feet from the ground, and supported at the other end by a stirrup iron, for hanging up the carcases of the oxen until they are ready to be removed. Pegs and hooks are fixed to the roof and walls for hanging up the carcases of calves, sheep and lambs. The following section and ground plan (Figs. 4 and 5) will further explain all these arrangements. The floors are paved with stone, and the joints well cemented. Small openings in the lower part of the door admit

[merged small][ocr errors][ocr errors][ocr errors][ocr errors][merged small][graphic][merged small][merged small][graphic][ocr errors]

arrangement of the roof and door keeps the interior of each slaughter-house some degrees cooler than the external air, which is found to be far more effectual in preserving the meat from blow-flies in summer, than by enclosing it in canvass, perforated zinc, or other similar contrivances.

An abundant supply of water is required for every part of the abattoir. This is furnished by a well, and is pumped up bv a steam-engine r, into reservoirs G G. (Fig. 2.)

As the number of oxen taken into the five abattoirs of Paris is at least 75,000 per annum, the quantity of water required per day is, from about 8,400 to 10,500 cubic feet. But as the consumption is by no means uniform, it being very great on certain days of the week, and ceasing almost entirely on other days, it is necessary to keep up a supply in the reservoirs. Each abattoir is furnished with two, the larger of which is of the capacity of 6,300 cubic feet, and they are placed at such an elevation, that all the pipes distributed over the abattoirs are constantly supplied.

The superfluous fat and fatty parts of the animals which cannot be used as food, are melted down for the purposes of the tallow-chandler, soap-maker, &c. This is done in the melting-houses, H, which contain

[ocr errors]

coppers of the capacity of from ten cwt. to forty cwt. of tallow. Under the same roof are places where tripe is prepared for sale.

The offal and refuse animal matters are collected from the various lay-stalls, slaughter-houses, &c. every day into the yard or shed I, (Fig. 2,) which is paved, and the joints between the stones made tight with cement. This court is cleared out and well washed if possible every day, to prevent any ill odour. The other letters of reference in Fig. 2. are K warehouses, L lieux d'aisance, M vaults under the terrace, N coachhouses and stables.

In addition to these arrangements, each abattoir is furnished with a capacious sewer, not shown in the plan, for receiving the various liquid animal matters from the lay-stalls, slaughter-houses, &c. This sewer is formed of hard gritty sandstone, and is three feet wide, and six feet high. The drains which lead into it from the various sections of the abattoir, are furnished at their upper part with a grating, sunk a little below the pavement, fitting into a short wide tube of wliich the lower extremity dips into a basin, and thus acts as a valve or stinktrap, (Fig. 7,) and effectually prevents gas from the sewer from rising up Fj 7 into any part of the abat; .>■;."■;.■ ^. toir. It will be seen from

the diagram that the liquid matters which pass through the grating, fall into the basin and then overflow into the drain.

The revenues of the abattoirs are considerable. The butehers are charged six franes per head for all the oxen slaughtered; which, on 75,000 or 80,000 oxen, produces an annual revenue of nearly 500,000 franes. After paying all expenses, a considerable revenue goes to the municipal purse. The new system is also far more economical to the butehers themselves than the old method. It has been found also that by withdrawing the slaughterers from the public gaze, and insisting upon habits of neatness and order, the manners of this class of men have been greatly improved.

Abattoirs have been erected in the neighbourhood of all the large towns of France, and we hope the time is not distant, when London and the principal towns of Great Britain will be similarly provided. ABUTMENT—See Bridge. ACETIC ACID (from the Latin acetum, vinegar) is important in a manufacturing point of view, from its being the sour principle of vinegar. This acid occurs ready formed in some plants, and is produced during the spontaneous fermentation of many vegetable and animal juices. All liquids containing aleohol are capable of passing into the state of vinegar; and hence the manufacturer finds it convenient to employ those liquors in which the vinous fermentation is complete,—such as wine, beer, &c. When these liquids are exposed to the atmosphere, at a certain temperature, a new chemical change is induced, whereby oxygen is absorbed, and the aleohol gradually passes into acetic acid. This acid, as it exists in combina

Bs

tion with certain bases, is composed of 4 atoms of carbon, 3 atoms of hydrogen, and 3 of oxygen; but in this state, which is called anhydrous, or without water, it has never been obtained separately. In combination with one atom of water, it forms what is called glacial acetic acid, from the circumstance of its freezing at a temperature of about 45°. This acid may be represented by the formula, C4 H, 03 + HO; that is, 4 atoms of carbon, 3 atoms of hydrogen, 3 atoms of oxygen, plus 1 atom of water. Now, as aleohol is composed of C4 H« 0., its conversion into anhydrous acetic acid will be seen to consist in the abstraction of two atoms of hydrogen, and the addition of two atoms of oxygen. Or, if we take 100 parts of aleohol, and 100 parts of hydiated acetic acid, we get—

52.6 carbon. 40.6 carbon.

12.9 hydrogen. 6.O hydrogen.

31.5 oxygen. 52.8 oxygen.

10O0 parts of aleohol. 1000 .fParts ?? "grated ( acetic acid.

Hence it will be seen, that acetic acid contains the same elements as aleohol, but in different proportions; there being less carbon and hydrogen, but more oxygen. It was formerly supposed that this change was brought about by the aleohol being deprived of a portion of its carbon and hydrogen, while the oxygen remained the same. More recent inquiries have proved that no carbonic acid is formed during the process; but that a portion of the oxygen of the atmosphere combines with a portion of the hydrogen of the aleohol to form water. The aleohol, thus partially deprived of its hydrogen, forms a new compound, named aldehyde, which contains the same proportions of carbon and hydrogen as acetic acid, but less oxygen; the deficient quantity of oxygen being afterwards supplied by the atmosphere.

The conversion of aleohol into acetic acid may be shown by a beautiful experiment,—the basis of a manufacturing process adopted in Germany. When vapour of aleohol is brought into contact with a black powder obtained by mixing muriate of platinum, potash, and aleohol, vinegar is rapidly formed; the powder absorbing and condensing the oxygen of the atmosphere, so as to enable the aleoholic vapour to combine with it. The arrangement is as follows :— Under a large glass case a number of earthen dishes, containing dilute aleohol, are arranged on shelves, one above another, and over each dish is suspended a portion of the moist platinum powder. A temperature of from 68° to 86° Fahr. is maintained, and the evaporation of the fluid is promoted by hanging several strips of porous paper in the case with their lower edges dipping into the dishes, whereby a greatly increased amount of evaporating surface is obtained. In a few minutes the mutual action of the platinum powder and the aleohol will cause an increase of temperature, accompanied by the formation of acid vapours, which condense on the sides of the case, and trickle down to the bottom. This action continues unl il all the oxygen in the air of the case is consumed;

but the action is renewed by a fresh supply of air. If the case contain 1,000 cubic inches of air, this will suffice to oxidize 110 grains of absolute aleohol, and will produce 122 grains of anhydrous acetic acid, and 64| grains of water. The platinum powder does not waste, and may, therefore, be used over and over again.1

In the general process of vinegar-making, some cheap ferment is usually made to take the place of the platinum powder in the above experiment. There are many substances containing nitrogen which answer this purpose, such as gluten, mucus, vinegar itself, or substances containing it, such as yeast, sour dough, sour beer, but especially sour bread soaked in vinegar. These substances, being in a state of inodorous putrefaction, decay, or oxidation, draw the aleohol into the circle of their decomposition, just as decaying wood causes fresh wood around it to assume the same condition. When the aleoholic liquor, mixed with the ferment, is exposed at a proper temperature to the atmosphere, the ferment is supposed to absorb oxygen from the air, and to transfer it to the aleohol. The liquor soon becomes turbid; slimy particles form in it, and collect as a scum on the surface; this scum thickens, and, after a time, falls to the bottom. The Germans call it the vinegar mother, and use it for the purpose of exciting acetification in fresh liquor. The temperature of the mass rises, and diffuses a peculiar aroma over the place. When all the aleohol has been converted into acetic acid, the action ceases, the temperature declines to that of the surrounding air, the liquor becomes bright, and may be drawn off as viregar fit for the market.

All substances, then, that can be made to undergo acetous fermentation, either because they contain sugar, or that sugar is formed in them from starch, can be employed in the manufacture of vinegar;—as, for example, in malt, the starch is converted into sugar by the process of mashing, and the sugar is converted into aleohol by vinous fermentation.—[See Ferilentatiox.]

According to the substance employed, the variety of vinegar receives its name in commerce, as—1. Wine vinegar, which is prepared from wine, and contains acetic acid, tartaric acid, and a minute portion of acetic ether, to which the pleasant aroma of this kind of vinegar is due. 2. Artificial Wine vinegar, or Alcohot vinegar. This is prepared from spirits, and consists almost entirely of acetic acid, water and a small portion of acetic ether. 3. Fruit vinegar, or Cider vinegar, from the fermented juice of apples; this vinegar contains, besides acetic acid, malic acid, which is a source of acidity in apples and many other fruits. 4. Beer, Malt or Corn vinegar, formed from the extract of malt, and contains, in addition to acetic acid, nearly all the constituents of beer, such as the phosphates of lime and magnesia, gum and an extractive substance which imparts colour, and causes the vinegar to froth on being shaken. There is a fifth variety of vinegar produced by the destructive

(1) Urc's Dictionary of Arts aid Manufactures.

distillation of wood, but as the formation of this acid does not resemble that of acetic, we must refer to

PyROLIGNEOUS ACID.

Vinegar is manufactured by one of two distinct methods, called the stow and the quid method, the one requiring months, and the other days for the completion of the process. We will first describe the manufacture by the slow method.

In countries where much wine is grown, vinegar is manufactured chiefly or entirely from the inferior sorts, and from the refuse of the wine-grower. Orleans in France is celebrated for its vinegars. The acetous fermentation is carried on in casks, called mothers, of about the capacity of an old English hogshead, laid horizontally on tressels, in ranks close together. Each cask has two holes at the upper part of the front end: one two inches in diameter, for pouring in the charge and drawing off the vinegar; the other of smaller size, for allowing the air to escape while the charge is being poured in by means of a funnel, which fills the large hole. The charge occupies about two-thirds of the cask. The wine is clarified before being poured into the casks, by being strained through a tun filled with chips of beechwood, well pressed down. Should the vinegar not be perfectly clear, it is filtered in a similar manner. The fermenting room is kept at a steady temperature of 86°, by means of brick flues, or hot-water pipes, running along the sides of the floor, the furnace being on the outside to prevent any contamination of the vinegar from smoke or dust. The air of the fermenting room is renewed by moderate ventilation, but the air holes are shut in windy weather, or when the temperature is too low. To see whether the fermentation is complete, a white stick, bent at one end, is plunged into the liquor. If on drawing it out it be covered with a white, thick, pearly froth, the acetification is considered complete; if the froth be red, it is not complete, in which case fresh wine is added, or the temperature is raised. This method occupies several weeks.

In the United Kingdom, vinegar is almost exclusively manufactured from malt. A sweet wort is obtained by mashing the malt as in brewing; [See Brewing;] a ferment is added, and the wash or gyle, as it is then called, is acetified either by storing or fielding. By the first method, casks containing the wash arc arranged in close rooms, heated by steam-pipes or stoves. By the second method, the casks, each containing rather more than 100 gallons, are placed on their sides in the open air, with the bung-holes up, and arranged in long parallel rows, two or more deep, with narrow walks between, forming what is called a field. These casks are supplied by means of a flexible pipe or hose, in connexion with the great wash-tun in the brew-house. The wash usually requires several months for its complete acetification, during which time the bung-holes are left open in fine weather, but covered with a tile during rainy weather. When the acetification is complete, the vinegar is removed from the casks by means of a sypnon into a shoot on the ground, whence it is pumped into a stove vat within

doors. Before the vinegar is fit for the market, it is clarified by being passed slowly and repeatedly through

[graphic]

Fig. S. VINEGAR P1ELD

large vats, called rapes, which contain a compact heap of the stalks and skins of raisins, called rape, the refuse of the British wine manufacture. In order to obtain a constant supply of this article, the maltvinegar making is associated with the manufacture of British wines, called sweets by the excise.1

In some places a solution of sugar is used in vinegar making, instead of an infusion of malt. One recipe directs 1 part of sugar to be dissolved in 6 parts of water, to which 1 part of brandy or other strong spirit is to be added together with a little yeast. This mixture is poured into a large cask with the bung-hole left open, and kept at a temperature of from 70° to 80°. The acetification will be complete in a month or six wecks, when the clear vinegar may be drawn off. Liebig recommends a mixture of 100 parts water, 13 brandy, 4 honey, and 1 of tartar; or 120 water, 12 brandy, 3 brown sugar, 1 tartar, and half a part of sour dough, to be left for some weeks in a warm place.

It is not necessary to give any further details respecting the slow method, which is very inferior to the quick method now to be described. This has been carried to such a point of perfection, that it is scarcely possible to imagine any further improvement; for the highest aim of the manufacturer, the conversion of the aleohol into acetic acid without loss, and in the shortest possible time, seems to have been completely accomplished. This method originated with Boerhaave, long before the true chemical theory of the formation of vinegar had been obtained. He employed in the manufacture two large casks of the same size, each open at the top, and placed upright on the frame of the vinegar-room. These vessels were filled with the stalks and husks of grapes, and

(1) A detailed account of Messrs. Heaufoy's Vinegar and UritishWine Factory will be found in one of Mr. Dodd's amusing Factory Visit?, in the Penny Magazine, No. 67g.

« السابقةمتابعة »