Imatges de pàgina
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AAM, AUM, or Anim, a measure for liquids, used at Amsterdam, Antwerp, Hamburgh, Frankfort, &c. At Amsterdam it is nearly equal to 41 English wine gallons, at Antwerp to 36. ditto, at Hamburgh to 384 ditto, and at Frankfort to 39 ditto.

ABANDONMENT, in commerce and navigation, is used to express the abandoning or surrendering of the ship or goods insured to the insurer.

It is held, by the law of England, that the insured has the right to abandon, and to compel the insurers to pay the whole value of the thing insured, in every case “ where, by the happening of any of the misfortunes or perils insured against, the voyage is lost, or not worth pursuing, and the projected adventure is frustrated; or where the thing insured is so damaged and spoiled as to be of little or no value to the owner; or where the salvage is very high; or where what is saved is of less value than the freight; or where further expense is necessary, and the insurer will not undertake to pay that expense,” &c. --( Marshall, book i. cap. 13. $ 1.)

Abandonment very frequently takes place in cases of capture: the loss is then total, and no question can arise in respect to it. In cases, however, in which a ship and cargo are recaptured within such a time that the object of the voyage is not lost, the insured is not entitled to abandon. The mere stranding of a ship is not deemed of itself such a loss as will justify an abandonment. If by some fortunate accident, by the exertions of the crew, or by any borrowed assistance, the ship be got off and rendered capable of continuing her voyage, it is not a total loss, and the insurers are only liable for the expenses occasioned by the stranding. It is only where the stranding is followed by shipwreck, or in any other way renders the ship incapable of prosecuting her voyage, that the insured can abandon.

It has been decided, that damage sustained in a voyage to the extent of forty-eight per cent. of the value of the ship did not entitle the insured to abandon. be damaged in the course of a voyage, and it appears that what has been saved is less than the amount of freight, it is held to be a total loss. -- (Park on Insurance, cap. 9.)

When by the occurrence of any of the perils insured against the insured has acquired a right to abandon, he is at liberty either to abandon or not, as he thinks proper. "He is in no case bound to abandon; but if he make an election, and resolve to abandon, he must abide by his resolution, and has no longer the power to claim for a partial loss. In some foreign countries specific periods are fixed by law within which the insured, after being informed of the loss, must elect either to abandon or not. In this country, however, no particular period is fixed for this purpose ; but the rule is, that if the insured determine to abandon, he must intimate such determination to the insurers within a reasonable period after he has got intelligence of the loss, - any unnecessary delay in making this intimation being interpreted to mean that he has decided not to abandon.

No particular form or solemnity is required in giving notice of an abandonment. It may be given either to the underwriter himself, or the agent who subscribed for him.

The effect of an abandonment is to vest all the rights of the insured in the insurers. The latter become the legal owners of the ship, and as such are liable for all her

future outgoings, and entitled to her future earnings. An abandonment, when once made, is irrerocable.

B

If a cargo

In case of a shipwreck or other misfortune, the captain and crew are bound to exert themselves to the utmost to save as much property as possible; and to enable them to do this without prejudice to the right of abandonment, our policies provide that, “in case of any loss or misfortune, the insured, their factors, servants, and assigns, shall be at liberty to sue and labour about the defence, safeguard, and recovery of the goods, and merchandises, and ship, &c., without prejudice to the insurance, to the charges whereof the insurers agree to contribute, each according to the rate and quantity of his subscription.”

“ From the nature of his situation,” says Mr. Serjeant Marshall, “ the captain has an implied authority, not only from the insured, but also from the insurers and all others interested in the ship or cargo, in case of misfortune, to do whatever he thinks most conducive to the general interest of all concerned, and they are all bound by his acts. Therefore, if the ship be disabled by stress of weather, or any other peril of the sea, the captain may hire another vessel for the transport of the goods to their port of destination, if he think it for the interest of all concerned that he should do so; or he may, upon a capture, appeal against a sentence of condemnation, or carry on any other proceedings for the recovery of the ship and cargo, provided he has a probable ground for doing so; or he may, upon the loss of the ship, invest the produce of the goods saved in other goods, which he may ship for bis original port of destination ; for whatever is recovered of the effects insured, the captain is accountable to the insurers. If the insured neglect to abandon when he has it in his power to do so, he adopts the acts of the captain, and he is bound by them. If, on the other hand, the insurers, after notice of abandonment, suffer the captain to continue in the management, he becomes their agent, and they are bound by his acts.”

As to the sailors, when a misfortune happens, they are bound to save and preserve the merchandise to the best of their power, and while they are so employed they are entitled to wages, so far, at least, as what is saved will allow; but if they refuse to assist in this, they shall have neither wages nor reward. In this the Rhodian law, and the laws of Oleron, Wisby, and the Hanse Towns, agree.

The policy of the practice of abandonment seems very questionable. The object of an insurance is to render the insurer liable for whatever loss or damage may be incurred. But this object does not seem to be promoted by compelling him to pay as for a total loss, when, in fact, the loss is only partial. The captain and crew of the ship are selected by the owners, are their servants, and are responsible to them for their proceedings. But in the event of a ship being stranded, and so damaged that the owners are entitled to abandon, the captain and crew become the servants of the underwriters, who had nothing to do with their appointment, and to whom they are most probably altogether unknown. It is admitted that a regulation of this sort can hardly fail of leading, and has inded frequently led, to very great abuses. We, therefore, are inclined to think that abandunment ought not to be allowed where any property is known to exist; but that suclrproperty should continue at the disposal of the owners and their agents, and that the undewriters should be liable only for the damage really incurred. The first case that cai le before the British courts with respect to abandonment was decided by Lord Hardwiche, in 1744. Mr. Justice Buller appears to have concurred in the opinion now stated, that abandonment should not ve been allowed in cases where the

loss is not total. For further information as to this subject, see the excellent works of Mr. Serjer at Marshall (book i. cap. 13.), and of Mr. Justice Park (cap. 9.) via the Law of Insurance

ABATEMENT, or RFBATE, is the name sometimes given to a discount allowed tıp prompt payment; it is also sometimes used to express the deduction that is occasionai made at the custom-house fitranthe duties cha ble upon such goods as are damage i, and for loss in warehouses. This alles ance is tegulated by the act 3 & 4 Will. 4. c. $ 32. No abatement is made from the duties charged on coffee, currants, figs, guing grains, lemons, opium, oranges, raisins, pepper, tobacco, and wine.

ACACIA. See Gua ARABIC.

ACAPULCO, a celebrated sea-port on the western coast of Mexico, in lat. 160 29" N., long. 99° 46' W. Pop. 4,000 (?). “ It is," says Captain Hall, “ the very be u ideal of a harbour. It is easy of access; very capacious; the water not too deep; tie holding ground good; quite free from hidden dangers *; and as secure as the busin 'n the centre of Portsmouth dockyard." -( South America, ii. 172.) Previously to t le emancipation of Spanish America, a galleon or large ship, richly laden, was annual y sent from Acapulco' to Manilla, in the Philippine Islands, and at her return a fair w is held, which was much resorted to by strangers. But this sort of intercourse is 10 longer carried on, the trade to Manilla and all other places being now conducted by private individuals. The exports consist of bullion, cochineal, cocoa, wool, indigo, &c. Tre

* This is not quite accurate. There is one shoal on which a vessel was lost in 1781 ; but being laid down in the charts it is easily avoided. --(Humboldt, Nouvelle Espagne, iv. 90.)

Its

imports principally consist of cotton goods, hardware, articles of jewellery, raw and wrought silks, spices, and aromatics. Acapulco is extremely unhealthy; and though it be the principal port on the west coast of Mexico, its commerce is but inconsiderable. The navigation from Acapulco to Guayaquil and Callao is exceedingly tedious and difficult, so that there is but little intercourse between Mexico and Peru. The monies, weights, and measures are the saine as those of Spain; for which see Cadiz.

ACIDS, are a class of compounds which are distinguished from all others by the following properties. They are generally possessed of a very sharp and sour taste ; redden the infusions of blue vegetable colours; are often highly corrosive, and enter into combination with the alkalies, earths, and metallic oxides ; forming compounds in which the characters of the constituents are entirely destroyed, and new ones produced differing in every respect from those previously existing. The quality or strength of an acid is generally ascertained either by its specific gravity, which is found by means of the hydrometer, if the acid be liquid, or by the quantity of pure and dry subcarbonate of potass or soda, or of carbonate of lime (marble), which a given weight of the acid requires for its exact neutralisation. This latter process is termed Acidimetry, or the ascertaining the quantity of real acid existing in any of the liquid or crystallised acids.

The principal acids at present known are, the Acetic, Benzoic, Boracie, Bromic, Carbonic, Citric, Chloric, Cyanic, Fluoric, Ferroprussic, Gallic, Hydrobromic, Hydriodie, Iodic, Lactic, Malic, Margaric, Meconic, Muriatic or Ilyelrochloric, Nitrous, Nitric, Oleic, Oxalic, Phosphoric, Prussic or Hydrocyanic, Purpurie, Saccholactic, Suberic, Sulphurous, Sulphuric, Tartaric, Uric, and many others which it would be superfiuous to detail. It is the most important only of these, however, that will be liere treated of, and more particularly those employed in the arts and manufactures.

Acetic or pyroligneous acid. - This acid, in its pure and concentrated form, is obtained from the fluid maiter which pasmi's over in distillation, when wood is exposed to heat in close iron cylinders. This fluid is a mixture of acetic acid, tar, and a very volatile ether; from these the acid may be separated, after a second distillation, by saturating with chalk, and evaporating to dryness; an acetate of time is thus procured, which, by inixture with sulphate of soda (Glauber's salt), is decomposed, the resulting compounds being an insolubk sulphate of lime, and a very soluble acetate of soda ; these are easily separated from each oth p by solution in water and filtration; the acetate of soda being obtained in the crystalline form by evaptation. Troni thi, ur the acorate of lime, some manufacturers employing the former, others the latter, the deitic and is obtained by distillation with sulphuric acid (oil of vitriol); as thus procured, it is a colourless, volatile fuid, having a very pungent and refreshing odour, and a strong acid taste. strengti should be ascertained by the quantity of marble required for its neutralisation, as its specific gravity does not give a correct indication. It is employed in the preparation of the acetate of lead (sugar or lead), in many of the pharmaceutical compounds, and also as an antiseptic.

Vinegar is a impure and very dilute acetic acid, obtained by exposing either veak wines or infusions of raait to the air and a slow fermentation; it contains, besides the pure acid, a large quantity of colouring matter, sone nucilage, and a little spirit; from these it is readily separated hy distiliation. The impurities with which this distilled vinegar is sometimes adulterated, or with which it is accidentally contaminated, are oil of vitriol, added to increase the acidity, and oxides of tin or copper, arising from the vinegar hasing been distilled through tin or copper worms. These may be easily detecton; the oil of vitriol by the addition of a little solution of muriate of barytes to the distilled vinegar, which, should the acid be present, will cause a dense white precipitate ; and the oxides of tin or coppies by the addition of water impregnated with sulphureted hydrogen. Vinegar is employed in many culinary aud domestic operations, a also very largely in the manufacture of the carbonate of lead ( white lead).

Berenic acid-exists naturally, formed in the gum benzoin, and may be procured either by submitting the benzoio ir fine powder to repeated sublimations, or by digesting it with lime and water, straining of the clear solution, and adding inuriatic acid, which enters into coinbination with the lime, and the benzoic acid, being nearly isisoluble in water, falls is a white powder; this may be further purified by a sublime ation. Benzoic acid is of a beautiful pearly white cclour when pure, havery peculiar aromatic odour, and an acrid, acid, and bitter taste; it is used in making pastilles and pemuned incense. This acid also occurs in the balsams of Tolu ard Peru, and in the urine of the horse and cow.

Baracic acit - is found in an uueunbined state in many of the hot springs of Tuscany, as also at Sesso in the Flor ntive territory, from whence it has received the name of Sessolin. In Thibet, Persia, and Sonth. America, it occurs in combination with soda, and is imported from the former place into this country in a crystalline form, under the name of Tineal. The crystals are coated with a rancid, fatty substance, ant r Guit to be purified by ron solutions and cryshons; after which it is sold under thra' tion of borax (bi-borate of soda), 1 a hot solution of ks salt the boracic acid is readily obtained by the addition of sulphuric acid i otit excos; sulphate of soula is formed, and the boracic acid crystallists as the solution cools. When plasts, whose crystals are white, and have an unctuous greasy teel; tb'y are soluble in alcohol, coinmunicating a green liline tv its tame; when fused it forms a transparent glass, and has been found by Mr. Faraday to imite with the oxide of lead, producing a very uniform glass, free from all delicts, and well adapted for the purposs of telescopes and other astronomical iustruments. Borax is much employed in the arts, particularly in metallurgic operations as a fux; also in enamelling, and in pharmacy. (See BURAX.)

Carbunic cuil.-- This acid occurs very abundantly in nature, combined with lime, magnesia, baryter, at al acid, fixed air, mepni' je acid; from any of these it is easies separated by the addition of nearly any of the other acids. 'In to uncombined fond it in a transparent, gaseous duíd, having a density o['1-53, atmospheric air being unity; it is absonlind to a considerable extent by water, and when the water is rendered slightly alkallie by the addition of carbonate of s d's, and a large quantity of gas forced into it by pressure, it forms the well-known refreshing urrerage soda water. This gas is also formed in very large quantities during combustion, respiration, and fermeutation. Carbonic acid gas is destructive of animal life and combustion, and from its great weight accumulates in the bottoms of deep wells, cellars, caves, &c., which have been closed for a long period, and numerous fatal accidents arise frequently to persons entering such places incautiously; the precaution should always be taken of introducing a lighted candle pris to the descent or entrance of any one ; for should the caveile be extinguished, it wonld be dangerous to enter until properly ventilated. The combinations of carbonic acid with the alkalies, earths, and metallic oxides are terinea carbonates.

Citric acid-exists in a free state in the juice of the lemon, lime, and other fruits, combined, however with mucilage, and sometimes a little sugar, which renders it, if required to be preserved for a long period, very liable to ferment; on this account the crystallised citric acid is to be preserred. It is pre

pared by saturating the lemon juice with chalk: the citric acid combines with the lime, forming an insoluble compound, while the carbonic acid is liberated; the insoluble citrate, after being well washed, is to be acted upon by dilute sulphuric acid, which forms sulphate of lime, and the citric acid enters into solution in the water; by filtration and evaporation the citric acid is obtained in colourless transparent crystals. The chief uses to which it is applied are as a preventive of sea scurvy, and in making refreshing acidulous or effervescing drinks; for which latter purposes it is peculiarly fitted from its very pleasant Navour.

Fluoric acid — is found in the well-known mineral suor spar in combination with lime; from which it is procured in the liquid form by distillation with dilute sulphuric acid in a leaden or silver retort ; the receiver should be of the same material as the retort, and kept cool by ice or snow.

This acid is gaseous in its pure form, highly corrosive, and intensely acid; it is rapidly absorbed by water, communicating its properties to that fluid. Its chief use is for etching on glass, which it corrodes with great rapidity. For this purpose a thin coating of wax is to be melted on the surface of the glass, and the sketch drawn by a fine hard-pointed instrument through the wax; the liquid acid is then poured on it, and after a short time, on the removal of the acid and coating, an etching will be found in the substance of the glass. A very excellent application of this property, possessed by fluoric acid, is in the roughing the shades for table lamps. All the metals, except silver, lead, and platina, are acted upon by this acid.

Gallic acid. - The source from which this acid is generally obtained is the nut gall, a hard protuberance produced on the oak by the puncture of insects. The most simple method of procuring the acid in its pure form is to submit the galls in fine powder to sublimation in a retort, taking care that the heat be applied slowly and with caution; the other processes require a very long period for their completion. When pure, gallic acid has a white and silky appearance, and a highly astringent and slightly acid taste. The nut galls, which owe their properties to the gallic acid they contain, are employed very extensively in the arts, for dyeing and staining silks, cloths, and woods of a black colour; this is owing to its forming with the oxide of iron an intense black precipitate. Writing ink is made on the same principle: a very excellent receipt of the late Dr. Black's is, to take 3 oz. of the best Aleppo galls in fne powder, 1 oz. sul. phate of irou (green vítrivl), 1 oz. logwood finely rasped, 1 oz. gum arabic, one pint of the best vinegar, one pint of soft water, and 8 or 10 cloves; in this case the black precipitate is kept suspended by the gum.

Ilydriodic acid, -a compound of iodine and hydrogen, -in its separate form is of very little importance in the arts; its combinations with potass, soda, and other of the metallic oxides, will be treated of herediler.

Milic acid - exists in the juices of many fruits, particularly the apple, as also in the berries of the service and mountain ash.

Meconic acid -- is found in opium, in combination with morphia, forming the meconate of morphia, on which the action of opium principally depends.

Muriatic acid, or spirits of salts. — This acid (the hydrochloric of the French chemists) is manufactured from the chloride of sodium (dry sea salt), by the action of sulphuric acid (oil of vitriol). The most eco. nomical proportions are 20 pounds of fused salt, and 20 pounds of oil of vitriol previously mixed with an equal weight of water ; these are placed in an iron or earthen pot, to which an earthen head and receiver are adapted, and submitted to distillation ; the muriatic acid passes over in the vaporous forni, and may be easily condensed. The liquid acid thus obtained should have a specific gravity of 1:17, water being equal to 100; it has a strong acid taste, and a slight yellow colour; this is owing to a small quantity of oxide of iron. By redistillation in a glass retort at a low temperature, it may be obtained perfectly pure and colourless. It sometimes contains a little sulphuric acid ; this is detected by a solution of muriate of barytes. Muriatic acid, in its uncombined state, is an invisible elastic gas, having a very strong affinity for water, that Auid absorbing, at a temperature of 400 Fahrenheit, 480 times its voluine, and the resulting liquid acid has a density of 121. So great is this attraction for water, that when the gas is liberated into the air, it combines with the moisture always present in that medium, forming dense white vapours. Its combinations with the alkalies, &c., are termed muriates; those of the greatest importance are the muriates of tin, ammonia, barytes, and sea salt. The test for the presence of muriatic acid in any liquid is the nitrate of silver (lunar caustic), which causes a curdy white precipitate.

Nitric acid, or aquafortis. -- This, which is one of the most useful acids with which the chemist is acquainted, is prepared by acting upon salt petre (nitric or nitrate of potass) with oil of vitriol: the proportions best suited for this purpose are three parts by weight of nitre and two of oil of vitriol; or 100 nitre, and 60 oil of vitriol previously diluted with 20 of water; either of these proportions will produce a very excellent acid. When submitted to distillation, which should be conducied in earthen or glass vessels, the nitric acid passes over in the form of vapour, and a bisulphate of potass (sal mixum) remains in the retort.

Nitric acid of commerce has usually a dark orange-red colour, giving off copious fumes, and having a specific gravity of 150, water being 100. It is strongly acid and highly corrosive. It may be obtained perfectly colourless by a second distillation, rejecting the first portion that passes over. It is much em. ployed in the arts, for etching on copper-plates for engraving; also, for the separation of silver from gold, in the process of quartation. In pharmacy and surgery it is extensively used, and is employed for destroying contagious effluvia. Combined with muriatic acid, it forms aqua regia (nitro-muriatic acid), used as a solvent for guld, platina, &c. This acid is frequently contaminated with the muriatic and sul. phuric acids; these may be detected by the following methods. - A portion of the suspected acid should be diluted with three or four times its volume of distilled water, and divided into two glasses; to one of which nitrate of silver (lunar caustic in solution) is to be added, and to the other nitrate of barytes: if muriatic acid be present, a white curdy precipitate will be thrown down by the former; and if sulphuric, a white granular precipitate by the latter.

Oxalic acid - occurs in combination with potass as binoxalate of potass in the different varieties of sorrel, from whence the binoxalate of potass has been termed salt of sorrel. This acid is usually prepared by the action of nitric acid upon sugar, evaporating the solution, after the action has ceased, to the consistence of a syrup, and redissolving and recrystallising the crystals which are thus procured.

It is sold in small white acicular crystals, of a strongly acid taste and highly poisonous, and sometimes in its external appearance bears a strong similarity to Epsom salts (sulphate of inaguesia), which it has been unfortunately frequently mistaken for. It is instantly distinguished froin Epsom salts by placing a small crystal upon the tongue; when its strong acid taste, compared with the nauseous bitter of the sulphate of magnesia, will be quite a sufficient criterion. In cases of poisoning, however, by this acid, lime or chalk, mixed with water to form a cream, should be immediately administered, the combinations of oxalic acid with these substances being perfectly inert. It is employed in removing ink-stains, iron moulds, &c. from linen and leather; the best proportions for these purposes are 1 oz. of the acid to a pint of water. The must delicate test of the presence of oxalic acid is a salt of lime or lime-water, with either of which it forms a white precipitate, insoluble in water, but soluble in acids. Its combinations are termed oxalates.

Phosphoric acid -- is of very little importance in a commercial point of view, except as forming with lime the earth of bones (phosphate of lime). It is prepared by heating bones to whiteness in a furnace; froin this phosphoric acid is obtained by the action of sulphuric acid, still combined, however, with a small quantity of lime. The action of nitric acid upon phosphorus, the latter being added gradually and in small pieces, yields this acid in a state of purity, its combinations are termed phosphates.

Prussic acid, or hydrocyanic acid. – This aciu, which is the most virulent and poisonous acid known, is eoutained in peach blossoms, bay leaves, and many other vegetable productions, which owe their peculiar

odour to the presence of prussic acid. For the purposes of medicine and chemistry, this arid is prepared either by distilling one part of the cyanuret of mercury, one part of muriatic acid of specifir gravity' l'15, and six parts of water, six parts of prussic acid being collected; or, by dissolving a certain weight of cyanuret of mercury, and passing a current of sulphureted hydrogen ihrough the solution, until the whole of the mercury shall be precipitated ; if an excess of sulphureted hydrogen should be present, a little carbonate of lead (white lead) will remove it; on filtering, a colourless prussic acid will be obtained. By the first process, which is the one followed at Apothecaries' Hall, the acid has a density 995, water being equal to 1000; by the latter, it may be procured of any required strength, depending on the quantity of cyanuret of mercury dissolved. The best test for the presence of this acid is, first to add a small quantity of the protosulphate of iron (solution of green vitriol), then a little solution of potassa, and lastly diluted sulphuric acid, if prussic acid be present, prussian blue will be formed. Its combinations are called prus. siates or hydrocyanates; when in its concentrated form, it is so rapid in its eflects that large animals have been killed in the short space of 80 seconds, or from a minute to a minute and a half.

Sulphurous acid - is formed whenever sulphur is burnt in atmospheric air: it is a suffocating and pungent pas, strongly acid, bleaches vegetable colours with great rapidity, and arrests the process of vinous fermentation. For these purposes it is therefore very much employed, especially in bleaching woollen goods and straws. Fermeritation may be immediately arrested by burning a small quantity of sulphur in casks, and then racking off the wine while still fermenting into them; this frequently gives the wine a very unpleasant taste of sulphur, which is avoided by the use of sulphate of potass, made by impregnating a solution of potass with sulphurous acid gas.

Sulphuric acid, or oil of vitriol-called oil of vitriol from its having been formerly manufactured from green' vitriol (sulphate of iron). In some parts of the Continent this process is still followed. The method generally adopted in this country is to introduce nine parts of sulphur, intimately mixed with one part of nitre, in a state of active combustion, into large leaden chambers, the bottoms of which are covered with a stratum of water. Sulphurous and nitrous acid gases are generated, which entering into combination form a white crystalline solid, which falls to the bottom of the chamber; the instant that the water comes in contact with it, this solid is decomposed with a hissing noise and effervescence, sulphuric acid combines with the water, and nitrous gas is liberated, which combining with oxygen from the air of the chamber is converted into nitrous acid gas, again combines with sulphurous acid gas, and again falls to the bottom of the chamber: this process continues as long as the combustion of the sulphur is kept up, or as long as atmospheric air remains in the chamber; the nitrous acid merely serving as a means for the transference of oxygen from the atmosphere to the sulphurons acid to convert it into sulphuric acid. The water is removed from the chamber when of a certain strength, and replaced by fresh. These acid waters are then evaporated in leaden boilers, and finally concentrated in glass or platina vessels. As thus manufactured, sulphuric acid is a dense oily nuid, colourless, intensely acid, and highly corrosive, and has a specific gravity of 1,846, water being equal to 1,000. This acid is the most important with which we are acquainted; it is employed in the manufacture of the nitric, muriatic, acetic, phosphoric, citric, tartaric, and many other acids, also in the preparation of chlorine, for the manufacture of the bleaching powder (oxymuriate of lime or chloride of lime), for the preparation of sulphate of mercury, in the manufacture of calomel and corrosive sublimate, and in innumerable other chemical manufactures. in the practice of physic it is also very much employed. It usually contains a little oxide of lead, which is readily detected by diluting the acid with about four times its volume of water, and allowing the sulphate of lead to subside. Its combinations are denominated sulphates. The fuming sulphuric acid, as manus factured at Nordhausen, contains only one half the quantity of water in its composition.

Tartaric acid. - This acid is procured from the cream of tartar (bitartrate of potass), obtained by purifying the crust which separates during the fermentation of wines by solution and crystallisation. When this puriged bitartrate is dissolved, and lime or carbonate of lime added, an insoluble tartrate of lime falls, which after washing should be acted upon hy sulphuric acid, sulphate of lime is thus formed, aud the tartaric acid enters into solution, and may be obtained by evaporation and crystallisation. It is employed very much in the arts, in calico-printing, as also in making effervescing draughts and powders in pharmacy.

Uric acid - is an animal acid of very little importance, except in a scientific point of view: it exists in the excrement of serpents, to the amount of 95 per cent., and forms the basis of many of the urinary calculi and gravel. N. B. This article, and that on alkalies, has been furnished by an able practical chemist.

ACORNS (Ger. Eickeln, Eckern ; Fr. Glands ; It. Ghiande ; Sp. Bellotas ; Rus, Schedudii ; Lat. Gandes), the seed or fruit of the oak. Acorns formed a part of the food of man in early ages, and frequent allusion is made in the classics to this circumstance (Virgil, Georg. lib. i. lin. 8. ; Ovid, Met. lib. i. lin. 106, &c.). In some countries they are still used, in periods of scarcity, as a substitute for bread. With us they are now rarely used except for fattening hogs and poultry. They are said to make, when toasted, with the addition of a little fresh butter, one of the best substitutes for coffee, Their taste is astringent and bitter.

ACRE, a measure of land. The Imperial or standard English acre contains 4 roods, each rood 40 poles or perches, each pole 2724 square feet; and consequently each acre = 43,560 square feet. Previously to the introduction of the new system of weights and measures by the act 5 Geo. 4. cap 74., the acres in use in different parts of England varied considerably from each other and from the standard acre; but these customary measures are now abolished. The Scotch acre contains four roods, each rood 40 falls, and each fall 36 ells; the ell being equal to 3706 Imperial inches. Hence the Imperial is to the Scotch acre nearly as 1 to 11, one Scotch acre being equal to 1.261 Imperial acres. The Irish acre is equal to 1 acre, 2 roods, and 194 poles ; 304 Irish being equal to 49 Imperial acres. (See Weights and MEASURES.)

ADJUSTMENT, in commercial navigation, the settlement of a loss incurred by the insured.

In the case of a total loss, if the policy be an open one, the insurer is obliged to pay the goods accorda ing to their prime cost; that is, the invoice price, and all duties and expenses incurred till they are put on board, including the premium of insurance. Whether they might have arrived at a good or a bad market, is held by the law of England to be immaterial. The insurer is supposed to have insured a constant and not a variable sum ; and in the event of a loss occurring the insured is merely to be put into the mame situation in which he stood before the transaction began. If the policy be a valued one the practice is to adopt the valuation fixed in it in case of a total loss, unless the insurers can show that the insured had a colourable interest only, or that the goods were greatly over-valued. In the case of all partial losses the value of the goods must be proved.

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