MOON-TREFOIL. 



MORTAR. 



brmation of dew is so happily explained ; and 

 it is sufficient to say, that the moisture deposit- 

 ed upon the meat causes it to spoil much 

 sooner than if kept covered, when it would re- 

 main dry. Meats are constantly preserved by 

 simple drying; and even the mummies in the 

 dry caverns of Egypt have lasted thousands of 

 years, mainly from their depositories being 

 perfectly free from moisture. The preserving 

 agency of embalming is, perhaps, a secondary 

 consideration, when compared with the subse- 

 quent state of dryness in which the bodies are 

 kept. 



As to the notion of lunar influence on dis- 

 ease, which still counts numerous partisans, I 

 regard it as upon precisely the same footing as 

 the exploded doctrine of the agency of the 

 stars, so long and stoutly maintained. 



Upon the whole, therefore, I look upon it 

 as clearly demonstrable, upon established phi- 

 losophical principles, 



1st, That wet and dry weather are matters 

 regulated solely by changes of temperature, over 

 which the moon has no control : 



2d, That the mutual influence exerted be- 

 tween the earth and moon, as shown in the 

 ocean and atmospheric tides, depends upon the 

 play of another and entirely distinct principle, 

 namely, gravitation or attraction : 



3d, That most, if not all, the effects upon 

 animal and vegetable substances, popularly 

 ascribed to the action of the moon, are to be 

 traced to natural agencies, entirely independent 

 of this satellite. 



MOON-TREFOIL. A name for one of the 

 species of medick (Medicago arborea'). 



MOON WORT (Hotrychium, from botrys, a 

 bunch ; in reference to the form of the fructi- 

 fication, which is much like a bunch of 

 grapes). The species of this genus of ferns 

 are curious and interesting plants ; one only 

 is indigenous, the common moonwort (B. luna- 

 n'a), which is a perennial growing in moun- 

 tainous pastures or meadows. The root con- 

 sists of several simple, cylindrical, clustered or 

 whorled fibres. The herb is very smooth, a 

 little succulent, of a pale opaque green, erect, 

 not a span high. Leaf solitary, pinnate ; leaf- 

 A ets fan-shaped, notched. 



MOOR. An uncultivated surface of coun- 

 try, without trees, and with few grasses or 

 other herbage fit for pasture ; and usually con- 

 taining scattered plants of heath, with a dark 

 peaty soil. Moor lands are generally the least 

 fitted for culture of any description of surface, 

 not rocky or mountainous. Moors are covered 

 with a very thin layer of soft, black, sterile 

 soil ; and the subsoil is generally gravel or re- 

 tentive ferruginous clay. By the destruction 

 of the heath or other bad herbage, and by sow- 

 ing down with grass-seeds, they may be im- 

 proved. In many cases, also, trees will grow 

 on drained moors; in which case the soil ulti- 

 mately becomes ameliorated by the shade they 

 afford, and the fall and decay of their leaves. 

 See HEATH, MORASS, PEAT SOILS, and WASTE 

 LANDS. 



MOORBAND PAN. This is a name given 



in Scotland to an indurated combination of 



clay, small stones, and iron in a particular 



state, situated either immediately, or at some 



832 



distance below the path of the plough, and 

 which is nearly impervious to water. All in- 

 durated incrustations, however, formed under 

 the sole of the plough, says a writer in a valu- 

 able agricultural journal, are not nworband 

 pan. In good alluvial loam of greater depth 

 than the plough-furrow, and rendered adhesive 

 by pressure, an incrustation or firming of the 

 subsoil that is, the bottom upon which the 

 plough moves, is frequently formed by the sole 

 of the plough rubbing constantly on the soil at 

 the same depth. This incrustated earth can 

 retain water, but its effects on soils and plants 

 are innocuous compared to those of moorband 

 pan. Nevertheless, its disruption by deep 

 ploughing is of benefit to the soil, and we have 

 experienced it in very fine deep mould. From 

 an analysis by Mr. John Gray, of Dilston, of 

 two portions of moorband pan obtained from 

 Mylnfield Plain, 120 parts of one were found to 

 contain 34 of oxide of iron, 74 of silex, and 6 of 

 alumina or clay and loss; the other contained 

 43 parts of oxide of iron, 64 of silex, and 8 of 

 alumina and loss. 



MOOSE. See DEER. 



MOOSE-ELM. See ELM, RED. 



MOOSE-WOOD. The name of a species 

 of maple (Acer striatuin'), so called in the 

 northern section of the United States, but in 

 the Middle States known by the common name 

 of striped maple. 



MOOR-GRASS (Scsleria, named in honour 

 of M. Sesler, a physician and botanist of the 

 18th century). These are uninteresting grasses 

 in an agricultural point of view. 



MORASS. Moor lands saturated with water 

 to such an extent as not to bear the tread of 

 cattle. A morass is to a moor what a marsh 

 is to a meadow. It is evident that the drain- 

 age of morasses and moors, by lessening the 

 evaporation of water from their surfaces, must 

 tend to improve the local climate. See PEAT 

 and PLAXTATIOXS. 



MORDANT. Any substance used to fix 

 dyes or colouring " matters upon different 

 stuffs. 



MOREL (Germ, moschel). The MosrheUa es- 

 culenta is one of the few edible fungi which 

 may be used as food with safety. It occasion- 

 ally occurs in woods and orchards, whence 

 it finds its way to the markets; but it is of 

 comparatively rare occurrence. It has a hol- 

 low stalk an inch or two high, and a yellowish 

 or grayish indented head 2 or 3 inches deep. 

 See FUXGI, and MUSHROOMS. 



MORTAR. A well-known cement employed 

 for building purposes, which is thus described 

 by Dr. Thomson: "It is composed of quick* 

 lime and sand, reduced to a paste with water. 

 When dry it becomes as hard as stone, and as 

 durable; and adhering very strongly to the 

 surface of the stones which it is employed to 

 cement, the whole wall in fact becomes no- 

 thing else than one single stone". But this 

 effect is produced very imperfectly unless the 

 mortar be very well prepared. The lime ought 

 to be pure, completely free from carbonic acid, 

 and in the state of a very fine powder; the 

 sand should be free from clay, and partly in the 

 state of fine sand, and partly in that of gravel ; 

 the water should be pure, and if previously 



