AET 



85 



AFF 



cut (cciculut hippocastanum), and other 

 nearly allied species. 



-Esct'LiNE, an alkaline substance, ex- 

 tracted from the horsechesuut (trsculus). 



JS'scCLUS, the horsechesnut ; a genus of 

 shnibacfous plants, of the class hepttmdria. 

 and order monogynia. There are six spe- 

 cies, with some varieties ; natives of the 

 northern parts of Asia and America. Name 

 from etca, food. 



The bark of the common horsechesnut 



tree (^K. hippocastanum) is much es- 

 teemed on the Continent as a febrifuge ; 



and it is by some considered superior to 



Peruvian bark. This tree is now well 



known in Britain. 



JiSHNA, a sub-genus of neuropterous 

 insects (dragon-flies), included in the libel- 

 lula of Linnaeus. 



ESTHETICS, Gr. nifftfrjTiKO?, having 

 the power of perception by means of the 

 senses. In Ihefine arts, the science which 

 derives the first principles in all the arts 

 from the effects which certain combinations 

 have on the mind, as connected with nature 

 and right reason. It is intimately related 

 to sentiment, and links together with feeling 

 the different parts of a composition. 



JSSTIVAL, Lat. cestivatis, pertaining to 

 Bummer (cestas), e. g. sestival solstice. Ap- 

 plied also, 1. To plants which flower during 

 summer. 2. To diseases which appear du- 

 ring summer. 



ESTIVATION, Lat. cestivatio. 1. The ef- 

 fect produced by summer heat (cestas). 



3. The state of the bud before the evolution 

 of the crolla. 



JSSTUARIUM, Lat. from cestuo, to heat. 

 An apparatus for conveying heat. The term 

 is chiefly used by medical writers. 



AETHEOGAMOUS, from ai,#,5, and ya- 

 MOS, marriage. A term used to express 

 characteristically the nature of eryptogamic 

 plants. 



^THIOPS, a name given by the older 

 chemists to several black powders, on ac- 

 count of their colour ; e. g. cethiops mar- 

 tialit was the black deutoxide of iron ; 

 cethiops per se was the protoxide of mer- 

 cury ; cethiops animalis and vegetabttu were 

 the powders formed by the incineration of 

 animals and vegetables ! The term cethiops 

 mineral is still popularly used to denote 

 the black sulphuret of mercury, which is 

 formed by triturating mercury with sulphur, 

 till the whole forms a deep black powder. 



jTHUSA,/oor* parsley, or lesser hemlock, 

 a genus of plants of two species. The Bri- 

 tish species, .jE. cynapium, resembles parsley, 

 and is often mistaken for it: it is poisonous. 

 Class, pentundria, order, diyynia. Name 

 from aiQu}, to burn, on account of its acrid 

 quality. 



AETHRISCOFE, from oitfpto?, clear, and 



ovcOTreco, to view. An instrument con- 

 trived by Sir J. Leslie, to measure the vari- 

 ations of radiation in different states of the 

 atmosphere. It consists of the differential 

 thermometer, having one of the balls 

 excluded from the light, and the other 

 placed in a metallic cup, exposed to a 

 clear part of the sky; the heat radiates 

 from it rapidly, and the temperature falls; 

 exposed to a cloud the radiation is re- 

 turned, and there is no reduction of tem- 

 perature. 



JErioLOGY, from ainov, a cause, and 

 Aoyo-;, discourse. 1. A figure of speech, 

 whereby in relating an event, we unfold 



the causes of it. 2. The doctrine of 



causation. 



^ETITES, from oWb?, an eagle. The 

 lapis aguilce, or eagle stone : a variety of 

 the oxide of iron and clay. It is found in 

 nodular masses in the coal formations of 

 Great Britain, and is known to mineral- 

 ogists by the name of clay-iron ore. It 

 takes its name from a popular notion, that 

 the eagle carries it to her nest to prevent the 

 eggs from becoming rotten. 



AETo'MA,\Gr. from a TOC, an eagle. 



A'KTOS /The name given by Greek 

 architects to the tympanum of a pediment, 

 from the custom of decorating the apex or 

 ridge of the roof with figures of eagles. The 

 name thus first given to the ridge, was trans- 

 ferred to the pediment itself. 



AFFA, a weight used on the Guinea coast, 

 equal to an ounce troy. Half an alia is 

 called an eggebu. 



AFFECTATION, Lat. affectatio, from affecto, 

 to seek for overmuch. In the fitie arts, 

 overcharging any part of a composition with 

 an artificial and overstrained appearance, 

 in colouring, drawing, or action. 



AFFEER, in law, to assess or reduce an 

 arbitrary amercement to a precise sum, 

 according to the circumstances of the case. 



AFKEEKMENT, the act of affeering an 

 amercement. See AFFEER. 



AFFEEROR, \ In law, one of several per- 



AFFEERER, Vsons appointed in courts 



AFFERER, J leet, courts baron, 4c., to 

 settle the fines upon those who have been 

 guilty of faults arbitrarily punishable. See 

 AFFEER. 



AFFET'TO, AFFETUOSO, or CON AFFETTO, 

 Ital. from Lat. affecto. In music, a direc- 

 tion to perform certain notes in a soft and 

 affectionate manner, and therefore rather 

 inclined to slow than the reverse. 



AFFIDA'VIT, in law, a declaration upon 

 oath before a competent authority, more 

 particularly when reduced to writing and 

 signed by the party. 



The term is an old law verb in th* 



perfect tense; he made oath, from u.i 



and fides, faith; affido, I confirm bj 



oath. 



D 2 



