ABU ! 



1. Tn metaphysics, the operation of the 

 niinil when occupied with abstract ideas, 

 as when some particular part or property 

 of an object is considered apart from the 

 rest, e.g. as when the mind considers a 

 branch of a tree by itself, or the colour of 

 the leaves, as separate from their size or 



form 2. In logic, the power ot the mind 



in separating the combinations presented t* 

 it, bears the name of abstraction. Stewart. 



Abstraction may be regarded as the 

 science / ymtralizatiun, as it is by ab- 

 stractinc from individuals that which 

 is peculiar to each, and retaining what 

 is peculiar to all, that we come to form 

 the idea of species, and proceeding: in the 

 same way with species, we arrive at 

 genera; from thence we proceed to 

 orders and claws. 



3. In chemistry, the term denotes the 

 separation by heat of the volatile parts of 

 a compound. "When the part abstracted 

 is collected, the process is called distilla- 

 tion or sublimation, according as the pro- 

 cess is wet or dry. 



ABSTRIN'GEXT, Lat. abstringens. Medi- 

 cines which are used to resolve obstruc- 

 tions, concretions, &c., are called abstrin- 

 gents, e. g. soup. 



ABSURD, Lat. absvrdus (from ab and 

 turdu9, deaf), opposed to manifest truth. 

 In mathematics, a term employed in de- 

 monstrating converse propositions. The 

 proposition is not proved in a direct 

 manner from principles before laid down, 

 but the contrary of the proposition is 

 proved to be impossible or absurd, and 

 this indirectly proves the truth of the 

 proposition itself. Thus the fourth pro- 

 position of the first book of Euclid is 

 demonstrated by showing that if the 

 extremities of two right lines coincide, 

 the lines themselves will coincide in all 

 their parts, otherwise they would enclose 

 a space, which is absurd, being contrary 

 to the tenth axiom. This is called reductio 

 ad absurdum. 



AB'SUS, the trivial name of a small 

 Egyptian lotus (cassia aims). The pow- 

 dered seeds are used in the cure of 

 ophthalmia. 



ABU.N'DANT. Lat. ab-undans (from vnda, 

 a wave). In arithmetic, a number, the 

 sum of whose aliquot parts is greater than 

 the number itself, is called an abundant 

 number, e. g. 1, 2, 3, 4, 6, the aliquot 

 parts of 12, make the sum 1C. This is 

 opposed to a deficient number, as 14, the 

 aliquot parts of which are 1, 2, 7, the sum 

 of which is 10, and both ton perfect number, 

 which is equal to the sum of all its aliquot 

 cam, as 6, whose aliquot parts are 1, 2, 3. 

 ABUT'ILON, a genus of exotic shrubs, 

 containing 26 species ; class monadelphia, 

 order polyandria, natives of South Ai.e- 

 rica, East and "Wuct Indies. Senegal, 



A A 



Egypt, and Canaries. One species (A. Avi- 

 ceniue) is a native of the south of France 

 ABUTMENT, from abut, to meet (chiefly 

 used in describing the bounds or situation 

 of land). The extremity ; chiefly used to 

 denote the solid mound or pier erected 

 on the bank of a river, to support the end 

 of a bridge. Synonymes, land-stool, land- 

 pier. The term, however, often means 

 simply the masonry casing of this pier. 

 Among carpenters, the joining of two 

 pieces of timber is called an abutment. In 

 this the fibres of the wood are placed as 

 nearly as practicable at right angles to 

 each other. 



ABUT'TAL, the butting or boundary of 

 land ; a headland. See ABBUTTALS. 



ABYSS, t'rom */2uir<rof, without bottom ; 

 something profound, as it were bottom- 

 less; e.g. the ocean, hell (bottomless pit). 

 The term has been used by some to 

 denote a vast cavity filled with water, 

 which they supposed to exist in the 

 centre of the earth ; and by others, to 

 signify a deep mass of water, which 

 they conceived encompassed the earth 

 in its state of chaos. These waters 

 were, according to the same authori- 

 ties, collected by the Deity, into the 

 abyss in the centre of the earth, on the 

 third day of creation. Geology has 

 done much of late to correct our no- 

 tions on these subjects. 

 2. In heraldry, the centre of an escut- 

 cheon, e. g. " He bears azure, a fleur de 

 lis, in abyss," i.e. in the middle of the 



shield clear of everything else. 3. In 



archeology, the temple of Proserpine, so 

 called from the immense treasures it was 

 supposed to contain. 



ABTSSIN'IANS, a sect of Christians in 

 Abyssinia, who admit but one nature in 

 Jesus Christ, and reject the council of 

 Chalcedon. They are governed by a 

 bishop, called an abu*,(*. 



Ac. in Saxon, oak; the initial syllable 

 of names, as Acton, Oaktown. 



A.C., an abbrev. of Ante Christum (be- 

 fore Christ). 



ACAP'ALOT, the Tantalus Mexicantti, a 

 Mexican fowl. See ACALOT. 



ACA'CIA, Gr. otxexiai, from eixoifa, to 

 sharpen, the Egyptian-thorn, a genus of 

 shrubaceous plants, of the class /xrfypawiin, 

 and order ntoiitvcia. This genus contains 

 about 132 species, all natives of hot cli- 

 mates. 



The Chinese- make a yellow dye from 

 the flowers of one species of it, which 

 bears washing on silks. .From another 

 species of it (acaria wo\ we derive our 

 gum arabit, gum SCHCLTU!, Vi-.; and the 

 astringent medicinr called catechu is the 

 production of a species of the same tree 

 'acacia catechi.i, which is a natiri of 

 the East Indies 



