EAR 



EAR 



lbs. as would be necessaT7 to balance I 

 the steelyard. This is, however, only 

 a coarse measure for the convenience 

 of the farmer, to enable him to ascer- 

 tain the draught of two different 

 ploughs, &c. 



DYSENTERY (from rJi-f, difficulty, 

 and evrepa, bowels). A looseness of 

 the bowels, attended with great pain 

 and loss of strength, and endemic. 

 See Horse, Ox. 



DYSPEPSIA (from (5t;c, difficuUy, 

 and TvsnTLi, I digest). Disordered di- 

 gestion, loss of appetite, unnatural 

 appetite, &c. It is to be repaired by 

 simple diet, temperance, and exer- 

 cise. 



DYSPNCEA (from 6vg, difficulty, 

 and nvEu, I breathe). Difficulty of 

 breathing: a symptom of disease of 

 the chest or heart. 



E. 



EAR. In a horse, the ears should 

 be small, narrow, straight, and the 

 substance of them thin and delicate. 

 They should be placed on the very 

 top of the head ; and their points, 

 when pricked up, should be nearer 

 together than their roots. When a 

 horse carries his ears pointed for- 

 ward, he is said to have a bold or 

 brisk ear. In travelling, it is consid- 

 ered an advantage when the horse 

 keeps them firm. 



EARS OF GRAIN. The spike 

 of wheat, corn, barley. 



EARTH. In chemistry, those me- 

 tallic oxides which are colourless, 

 nearly or quite insoluble in water, 

 the metallic basis of which is obtain- 

 ed only with difficulty, and rapidly 

 oxidizes, are termed earths. The 

 entire list includes but ten species : 

 lime, magnesia, baryta, strontia, alu- 

 mina, glucina, thorina, zirconia, yt- 

 tria, and silica ; but of these lime, 

 alumina, and silica form the bulk of 

 the soils and rocks of the globe. 

 Magnesia is also rather abundant, 

 but most of the remainder are very 

 rare bodies. With the exception of 

 silica, which is an acid, they are ba- 

 ses. See the earths separately. 



EARTHS, :f HYSICAL PROPER- 

 TIES OF. The power of absorbing 

 24S 



moisture and heat, of transmitting 

 fluids, and drying into dust or a hard 

 mass, are termed the physical quali- 

 ties of soils, and contribute, in a great 

 measure, to their fertility. This sub- 

 ject has been well investigated by 

 Mr. Schubler. 



Capacity for holding Water. — If 

 soils of different kinds be wetted un- 

 til the fluid drops, it will be found 

 that 



1I)S. lbs. 



100 of dry sand retain 25 of water. 

 100 of calcareous sand 29 " 

 100 of loamy soil . . 40 " 

 100 of clay loam . . 50 " 

 100 of strong clay .79 " 

 100 of peat 100 and more. 



Good soils hold from forty to fifty 

 per cent, of water. 



Absorbing Poiver. — Soils not only 

 hold water, but absorb it from the air 

 unequally. Thus, a quantity spread 

 out to the same extent, 



lbs. 

 of sand, absorbed . of water, 

 of calcareous sand . 3 " 

 sandy loam ... 21 " 

 strong clay ... 30 " 

 garden mould ... 35 " 

 In the same way, they retain moist- 

 ure very unequally, sand losing it 

 four times more rapidly than mould. 

 Absorption of Gases. — A well-tilled 

 soil is continually absorbing from the 

 air gaseous matter, and its fertility 

 is, in a considerable degree, connect- 

 ed with this property. According to 

 Mr. Schubler, mould absorbs eleven 

 times, and clay nine times as fast as 

 sand. 



! Absorption of Heat. — Black, well- 

 tilled, and drained soils become more 

 rapidly heated, and to a greater de- 

 gree than such as are wet, of a light 

 ; colour, or baked. In the same way, 

 those that heat rapidly, cool rapidly, 

 and are more subject to frosts. By 

 experiments, mould cools in one third 

 the time, and clay in two thirds the 

 time of sand ; so that, if they be 

 equally heated, the sand will be warm 

 for hours after the mould is cold. 

 I Hence the latter absorbs dew and con- 

 tracts frost much more quickly than 

 I sandy soils. 



