EUP 



EVE 



ESPALIERS. " In horticulture, 

 trees trained by lattice-work or other 

 supports on the borders of beds, or 

 as hedges to enclose plots of ground. 

 They may serve to defend, in a great 

 measure, many tender plants from the 

 inclemencies of wind and weather. 

 The trees chiefly planted for espa- 

 liers are apples, pears, and plums. 

 The principal objects aimed at, how- 

 ever, in espaliers are to expose the 

 foliage and fruit of the plants or 

 trees more perfectly to the light and 

 sun, to prevent the branches from be- 

 ing blown about by the winds, and to 

 economize space by confining them 

 within definite limits." — Loudon. 



ESPARSETTE. Sainfoin. 



ESSENTIAL OILS. Oils which 

 impart flavour and odour to plants, 

 and are readily volatilized by heat. 

 Many, as peppermint, rose, lemon, 

 &c., are easily distilled by placing the 

 fresh herbs, »Scc., in water and apply- 

 ing heat. 



ETERIO. A compound fruit, the 

 ovaries of which are distinct and in- 

 dehiscent, upon a dry or fleshy re- 

 ceptacle, as the strawberry, rasp- 

 berry, &c. 



ETHER. Commonly this name is 

 applied to a highly volatile, inflam- 

 mable, and aromatic fluid, obtained 

 by distilling equal parts of alcohol and 

 sulphuric acid. But it also repre- 

 sents a class of organic compounds 

 having properties similar to ether and 

 alcohol, and containing a common 

 base or radical, Elhyl or Ethule (C4 

 Hj) ; of this common sulphuric ether 

 is an oxide. 



ETIOLATION. Blanching of ve- 

 getables. This is done by excluding 

 light either by earthing, as in the 

 case of celery, or tying up the leaves, 

 as with lettuce, endive, &c. 



EUDIOMETER (from evdia, calm 

 air, and fxtrpov, a measure). An in- 

 strument for the analysis of air and 

 gases, especially for the determina- 

 tion of the amount of oxygen. Dr. 

 lire's is the most esteemed. Dr. Hare, 

 of Philadelphia, is the author of a 

 very convenient eudiometer. 



EUPHORBIA. A genus of plants 

 commonly yielding a milky acrid 



juice ; many resemble the cactaccae. 

 Euphorbiacccc, the natural family, in- 

 cluding the euphorbia, crotons, cas- 

 tor-oil. India-rubber tree, &.c. 



EUPION. An inflammable, grea- 

 sy liquid, obtained from tar. 



EUSTACHIAN TUBE. A tube 

 passing from the interior of the ear 

 to the cavity of the mouth ; the stop- 

 page, by disease, is one cause of deaf- 

 ness. 



EVAPORATION. The passage 

 into vapour of fluids or solids. For 

 its production, heat must be absorb- 

 ed ; hence the rapidity of evaporation 

 is proportionate to the heat applied. 

 Water and other fluids evaporating 

 from the earth, or any surface, al- 

 ways produce cold by carrying away 

 a part of the heat of the solid ; hence 

 moist soils are cold. The activity of 

 evaporation is also influenced by 

 winds, which will double the amount 

 of water vaporized in a given time ; 

 hence winds dry rapidly and produce 

 great cold. It is also necessary for 

 free evaporation that the air be not 

 already full of vapour. See Dew Point. 

 When any atmosphere is surcharged 

 with the vapour of a particular fluid, 

 no more can evaporate ; but the va- 

 pours of other fluids rise freely. 



Plants are much affected by evap- 

 oration ; their leaves are always 

 throwing out large volumes of vapour 

 of water, derived from the ascending 

 sap ; in this way their juices are 

 thickened and fitted for nourishment. 

 When the air is too dry, they lan- 

 guish under excessive evaporation ; 

 when it is moist and hot for some 

 days, they become diseased, and smut, 

 rust, and similar fungi attack them 

 very destructively. 



'ihe moisture collected in the air 

 by the evaporation of water from the 

 earth, being cooled by northerly 

 winds, becomes condensed into rain 

 or snow, and falls back to the earth 

 again. See Clouds. 



EVERGREEN. Plants which put 

 out a succession of fresh leaves in- 

 stead of observing periods of rest. 

 They are best set out in the fall or 

 very early in spring. 



EVERLASTIjN'G PEA. Lathyrus 



96a 



