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DEFINITION OF TERMS. 



eyelids are inverted, or retracted, so as to 

 show their internal or red surface, and 

 cannot sufficiently cover the eye. 



Ectype, among antiquarians, an im- 

 pression of a medal, seal, or ring, or a 

 figured copy of an inscription, or other 

 ancient monument. 



Effluvum, in physiology, a term used 

 by philosophers and physicians to express 

 the minute particles which exhale from 

 most, if not all, terrestrial bodies in form 

 of insensible vapours. 



Empyrzuma., among chemists and 

 physicians, the fiery taste or offensive 

 smell which brandies, and some other bo- 

 dies prepared by fire, are impregnated 

 with. 



Emulsion^ in pharmacy, a soft liquid 

 substance, of a colour and consistence re- 

 sembling milk. 



Enceinte^ in fortification, is the wall or 

 rampart which surrounds a place, some- 

 times composed of bastians or curtains, 

 either faced or lined with brick or stone, 

 or only made of earth. The enceinte is 

 sometimes only flanked by round or 

 square towers, which is called a Roman 

 wall. 



Endemic, or Endemical diseases, 

 those to which the inhabitants of particu- 

 lar countries are subject, more than others, 

 on account of the air, water, situation, and 

 manner of living. 



Epigraphe, among antiquarians, de- 

 notes the inscriptions of a building, point- 

 ing out the time when, the persons by 

 whom, the uses, 4*c., for which it was 

 erected. 



Equilibrium, in mechanics, is when 

 the two ends of a lever or balance hang so 

 exactly even and level, as neither to as- 

 cend nor descend, but keep in a position 

 parallel to the horizon, which is occasion- 

 ed by their being charged with an equal 

 weight. 



Equiangular, in geometry, an epithet 

 given to figures whose angles are all 

 equal: such are square equilateral trian- 

 gles, &c. 



Equidifferent , numbers, are of two 

 kinds, 1. Continually equidistant is when, 

 in a series of three numbers, there is the 

 same difference between the first and se- 

 cond as there is between the second and 

 third, as 3, 6, 9. And 2. Discretely equi- 

 different is when, in a series of four num- 



bers or quantities, there is the same diffe- 

 rence between the first and second as there 

 is between the third and fourth: such are 

 3, 6, 7, 10. 



Equilateral, in general, something 

 that has equal sides, as an equilateral tri- 

 angle. 



Equilateral Hyperbola, one whose 

 transverse diameter is equal to its parame- 

 ter; and so all the other diameters, equal 

 to their parameters; in such an hyperbola, 

 the asymptotes always cut one another at 

 right angles in the centre. Its most sim- 

 ple equation, with regard to the trans- 

 verse axis, is y2=X2 — a2;and, with re- 

 gard 10 the conjugate, 5^2=^X2 X a2, 

 when a is the semi-transverse or semi- 

 conjugate. The length of the curve can- 

 not be found by means of the quadrature 

 of any space, of which a conic section is 

 in any part of the perameter. 



Errhines, in pharmacy, are medicines 

 which, when snuffed up the nose, pro- 

 mote a discharge from that part. 



Error, in law, signifies an error in 

 pleading, or in the process; and the writ 

 vvlilch is brought for remedy thereof, is 

 called a writ of error. A writ of error is 

 a commission to judges of a superior court, 

 by which they are authorized to examine 

 the record upon which a judgment was 

 given in an inferior court, and on such 

 examination, to affirm or reverse the 

 same, according to law. 



Eruca, in general, denotes caterpillars 

 of all kinds. 



Escalade^ in war, a furious attack of a 

 wall or a rampart, carried on with ladders; 

 to pass a ditch, or mount a rampart, with- 

 out proceeding in form, breaking ground, 

 or carrying on regular works to secure the 

 men. 



Estreat, is a true copy or note of some 

 original writing on record, and especially 

 of fines, and amercements imposed in the 

 rolls of a court, and extracted or drawn 

 out thence, and certified into the court of 

 exchequer: whereupon process is awarded 

 to the sheriflfto levy the same. 



Estrepem,ent, the spoil made by a ten- 

 ant for life, upon any lands or woods, to 

 the prejudice of the reversioner. 



Etching, is a manner of engraving on 

 copper, in which the line or stroke, in- 

 stead of being cut with a tool or graver, 

 are corroded with aquafortis. 



