EXCAMBION, or EXCHANGE. Excambion (a word con-nected with a large class of Low Latin and Romance forms, such as cambium, concambium, scambium, from Latin cambire, and Greek Ka/Afiew or /ca/xTrrav, to bend, turn, or fold) means in Scotch law the exchange of one heritable subject for another. Its meaning is extended by Lord Stair (Inst., i. 14, 1) to every case of exchange or barter, the permutatio or innominate contract (Datur res ut vicissim res detur) of the civil law, about which a fierce controversy raged between, the Proculian and Sabinian schools, as to whether it was truly a sale or a separate contract. Both schools used to quote the words of Homer, " And thence, too, wine was got by the long-haired Achaeans, some bartering it for bronze, and others the glistening steel, some hides, and some the cows them-selves, and some again slaves." This Roman contract was not constituted by consent, but by a formal stipulation ; it did not pass the property of movables, if the seller had not a title; and it was liable to be rescinded on proof of great inequality. In each of these features it has been modified by the modern law of most European states. Erskine says (Inst.,in. 3, 13), "This doctrine (of property not passing apart from title) may be equitable if directed Dnly against the party himself and his heir; but there could be little security in the commerce of movables if it were extended against a singular successor who had bona fide bought the subject from the party after the exchange." In other points, such as the risk of a subject being destroyed, or the remedies on breach of contract, permutation of mov-ables falls under the same rules as sale. The feudal lawyers amused themselves by discussing what name should be given to a contract in which the consideration consisted partly of money. They called it sale where major pars in pretio quam in re permutata. In the more limited sense of the exchange of heritable subjects, this contract received from the feudal law some advantages not given to sale. Thus, the burdensome right of the superior called protimesis, or pre-emption, did not apply to ex-cambions. The decuriones, or town councils, of the imperial municipio, were allowed to excamb, although they could not sell, the town-lands; and so with regard to church lands, the fundus dotalis, and other subjects partly withdrawn from commerce, excambions, but not sales, were permitted. Sovereigns, too, were allowed to excamb parts of the royal domain, although, as may be seen from the Scotch annexation and dissolution statutes of the 16th century, it required special authority to feu or alienate such subjects. The modern Scotch excambion may consist in the exchange of any heritable subjects whatever, e.g., a patronage or, what often occurs, a portion of a glebe for servitude. The older form of an excambion was in separate dispositions by each " copermutant," as Pothier calls him, in favour of the other, or sometimes mutual charters, each party becoming in turn vassal and superior. And according to the Leges Burgorum, c. 55, where lands or houses in burgh were exchanged, the form of delivering sasine consisted in the apertio and ciausio of the door, or the passing out and in of the parties respectively, each of whom gave two pennies (duo nummi) to the bailie. But this early form was soon superseded by one contract of excambion (originally drawn by Gilmour and Nisbet, and preserved in the MS. Style Book of Bain of Pitcarly) con-taining both dispositions, and proceeding generally on the narrative that the parcels of land excambed lie remote from or at least discontiguous to the mansion-house or the principal estate, and, being intersected by the lands of the other party, form a run-rig possession. This contract gives to each party a sufficient narrative of his own title to the lands he is disponing, and it provides, although the law implies this in every express excambion, that on eviction the contract and sasine shall be void and null, and that immediate " recurrency " or regress be given brevi manu to the lands which were excambed by the party evicted. Such real warrandice, as it is called, affects excambed land in the hands of singular successors who have purchased bona fide, and hence it is often provided that notice of any action of eviction shall be given to the excamber or his heirs. This exceptional severity reminds one of the civil law which distinguished between sale, where delivery of possession with warrandice against evic-tion was sufficient performance by the seller, and exchange, where an absolute title of property must be given. Writ-ing, however, is not, by the law of Scotland, essential to an excambion. Chiefly in favour of the class of cottars and small feuars, and for convenience in straightening marches, the law will consider the most informal memoranda, and even a verbal agreement, if supported by the subsequent possession. The power to excamb was gradually conferred on entailed proprietors. The Montgomery Act, which was passed in 1770, to facilitate agricultural improvements, per-mitted 50 acres arable and 100 acres not fit for the plough to be excambed. This was enlarged by the Rosebery Act in 1836, under which one-fourth of an entailed estate, not including the mansion-house, home farm, and policies, might be excambed, provided the heirs took no higher grassum than £200. The power was applied to the whole estate by the Ruth erf urd Act of 1848, and the necessary consents of substitute heirs are now regulated by the Entail Amendment Act of 1875.

Exchange, in English law, is defined as the mutual grant of equal interests, the one in consideration of the other. The peculiarities of this very ancient common law conveyance or assurance were—(1) equality of estates, not in value or in subject matter, but in legal right of owner-ship ; (2) the use of the word exchange (excambium, e.g., in Domesday book, hanc terram cambiavit Hugo, &c.); (3) that, though formal delivery of seisin was not required, possession or entry was required to complete the transaction by mak-ing it notorious: (4) that, in the case of incorporeal heredita-ments, and where the lands lay in different counties, a deed was required ; (5) an implied condition of re-entry on the lands of him whose title failed (Coke on Littleton, 50 a ; Blackstone by Sweet, ii. p. 323), the liability to re-entry affecting an alienee, but the right to re-enter being personal to the exchanger and his heirs. This condition, how-ever, did not long survive the statute Quia emptores ; and exchanges are now generally effected by mutual conveyances with the usual covenants for title, which the Act 8 and 9 Vict. c. 106 declares not to imply any condition, whether the word " exchange " be used in the testatum or not. Ex-changes are also very frequently made, by order of the in-closure commissioners, under the various Acts of Parliament for the inclosure, exchange, and improvement of lands, from 8 and 9 Vict. c. 118 to 31 and 32 Vict. c. 89 (see Cooke On Inclosures). In these cases, the property taken is simply impressed with the title of the property given in exchange. So also statutory exchanges are made under the Acts for the Sale and Exchange of Charity Estates, the Chari-table Trust Acts, from 16 and 17 Vict. e. 137 to 32 and 33 Vict. c. 110, which now apply to Eoman Catholic charities, formerly under 23 and 24 Vict. c. 134. There are also statutes enabling ecclesiastical corporations to ex-change, with the approval of the church estate commis-sioners. Powers of exchange are generally given to trustees under English settlements, and these are exercised by revo-cation of the original uses and appointment of new uses, all ancillary powers being given by implication under 23 and 24 Vict. c. 145 (see Davidson's Precedents in Conveyancing, vols, ii., iii., and v.).

In what may be called international conveyancing, the exchange of territories is accomplished by treaties, of which there is no fixed style. A well-known example is Art. XII. of the Treaty of Nimeguen, " Les terres en-clavées seront exchangees contre d'autres qui se trouveront plus proches et à la bienséance," &c. The Italian duchies and islands have very frequently been exchanged. Thus, in the Quadruple Alliance of 1720, Philip V. exchanged a reversionary title to Sicily for a reversionary title to Sardinia. The exchange of prisoners in war is often regulated by documents called cartels, which specify a certain agreed on value for each rank of prisoners. The transference of prisoners is often carried out by cartel ships, which, though prohibited from carrying cargo or passengers, are entitled to certain privileges. It was in the 17th century that this practice (which seems to have been unknown to Grotius) superseded the older one of ransom at the end of the war.

See Wheaton's Elements of International Law, Lawrence's edition, p. 590, and App. A. in Robinson's Adm. Pep., vol. iii. The early law of military exchange will be found discussed by Albericus Gentilis, De Jure Belli, cap. xvi., "De permutationibus et liberationibus." (W. C. S.)