MOUNTAINS

barrier, if the temperate regions contained as lofty mountains as the tropics. Mountain-ranges, however, decrease in height from the equator to the poles in relation to the snow-line.

The numerous attempts that have been made to generalise on the distribution of mountains on the globe have hitherto been almost unsuccessful. In America, the mountains take a general direction more or less parallel to the meridian, and for a distance of 8280 miles, from Patagonia to the Arctic Ocean, form a vast and precipitous range of lofty mountains, which follow the coast-line in South America, and spread somewhat out in North America, presenting everywhere throughout their course a tendency to separate into two or more parallel ridges, and giving to the whole continent the character of a precipitous and lofty western border, gradually lowering into an immense expanse of eastern lowlands. In the Old World, on the other hand, there is no single well-defined continuous chain connected with the coast-line. The principal ranges are grouped together in a Y-shaped form, the general direction of which is at right angles to the New World chain. The centre of the system in the Himalayas is the highest land in the hemisphere. From this, one arm radiates in a northeast direction, and terminates in the high land at Behring Straits: the other two take a westerly course; the one a little to the north, through the Caucasus, Carpathians, and Alps, to the Pyrenees; the other more to the south, through the immense chain of Central African mountains, and terminating

at Sierra Leone. Most of the principal secondary ranges have generally a direction more or less at right angles to this great mountain tract.

The inquiry into the origin of mountains is one that has received not a little attention. Geologists have shewn that the principal agents in altering the surface of the globe are denudation, which is always abrading and carrying to a lower level the exposed surfaces, and an internal force which is raising or depressing the existing strata, or bringing unstratified rocks to the surface. Whether the changes are the small and almost imperceptible alterations now taking place, or those recorded in the mighty mountains and deep valleys everywhere existing, denudation and internal force are the great producing causes. These give us two great classes of mountains.

1. Mountains produced by denudation. — The extent to which denudation has altered the surface of the globe can scarcely be imagined. All the stratified rocks are produced by its action; but these do not measure its full amount, for many of these beds have been deposited and denuded, not once or twice, but repeatedly, before they reached their present state. Masses of rock more indurated, or better defended from the wasting currents than those around, serve as indices of the extent of denudation. The most remarkable case of this kind, with which we are acquainted, is that of the three insulated mountains in Ross-shire-Suil Veinn, Coul Beg, and Coul More (fig. 1)-which are about 3000 feet high. The strata of the mountains

Fig. 1.-Suil Veinn, Coul Beg, and Coul More.-From Murchison's Siluria: London, J. Murray. are horizontal, like the courses of masonry in a pyramid, and their deep red colour is in striking contrast with the cold bluish hue of the gneiss which forms the plain, and on whose upturned edges the mountain-beds rest. It seems very probable, as Hugh Miller suggests, that when the formation of which these are relics (at one time considered as Old Red Sandstone, but now determined by Sir Roderick Murchison as being older than Silurian), was first raised above the waves, it covered, with an amazing thickness, the whole surface of the Highlands of Scotland, from Ben Lomond to the Maiden Paps of Caithness, but that subsequent denudation swept it all away, except in circumscribed districts, and in detached localities like these pyramidal hills.

2. Mountains produced by internal force.-These are of several kinds. (a.) Mountains of ejection, in which the internal force is conf ned to a point, so to speak, having the means of exhausting itself

through an opening in the surface. The lava, scoria, and stones ejected at this opening form a conical projection which, at least on the surface, is composed of strata sloping away from the crater. Volcanoes are mostly isolated conical hills, yet they chiefly occur in a somewhat tortuous linear series, on the mainland and islands which enclose the great Pacific Ocean. Vesuvius and the other European volcanoes are unconnected with this immense vol. canic tract. (b.) But the internal force may be diffused under a large tract or zone, which, if it obtain no relief from an opening, will be elevated in the mass. When the upheaval occurs to any extent, the strata are subjected to great tension. If they can bear it, a soft rounded mountain-chain is the resuit; but generally one or more series of cracks are formed, and into them igneous rocks are pushed, which, rising up into mountainchains, elevate the stratified rocks on their flanks, and perhaps as parallel ridges. Thus, the Andes

MOURNE MOUNTAINS-MOUSE

consist of the stratified rocks of various ages, lying in order on the granite and porphyry of which the mass of the range is composed. The position of the strata on such mountains supplies the means of determining, within definite limits, the period of upheaval. The newest strata that have been elevated on the sides of the mountain when it was formed, give a date antecedent to that at which the elevation took place, while the horizontal strata at the base of the mountain supply one subsequent to that event. Thus, the principal chain of the Alps was raised

during the period between the deposition of the Tertiary and that of the older recent deposits. (c.) But there is yet another way in which the upheaving internal force operates, viz., where it does not act at right angles to the surface, but rather obliquely, and, as it were, pushes the solid strata forwards, causing them to rise in huge folds, which, becoming permanent, form parallel ranges of mountains. The crust of the earth, in its present solid and brittle condition, is thus curved, in a greater or less degree, by the shock of every earthquake; it is well known that the trembling of the earth is produced by the progress of a wave of the solid crust; that the destruction of buildings is caused by the undulation; and that the wave has been so evident, that it has been described as producing a sickening feeling on the observer, as if the land were but thin ice heaving over water. This mode of mountain formation has been explained, when treating of the Appalachians (q. v.), which

Fig. 3.-The System of the Netherlands: 1, Silurian; 2, Coal Measures; 3, New Red Sandstone; 4, Oolite; 5, Chalk.

were thus formed. Many other ranges have had a similar origin, as some in Belgium and in the Southern Highlands of Scotland, as has been suggested by Mr Carruthers.

of volcanoes, may be an essential characteristic of contemporaneity. Nevertheless, Elie de Beaumont has classified the mountains of the world according to this parallelism, holding that the various groups are synchronous. The parallelism does not consist in having the same relations to the points of the compass-for these, as regards north and south, would be far from parallel-but is estimated in its relation to some imaginary great circle, which being drawn round the globe would divide it into equal hemispheres. Such circles he calls Great Circles of Reference. But beyond this, he goes a step further, and proposes a more refined classification, depending on a principle of geometrical symmetry, which he believes he has discovered among his great circles of reference. It is to be feared, however, that his geometrical speculations have little foundation in

MOURNING, a particular habit worn to express grief, especially for the decease of friends. The usages regarding mourning have varied much at different times and in different countries. Among the Jews, the duration of mourning for the dead was and the external indications of sorrow consisted in generally 7, but sometimes protracted to 30 days; weeping, tearing the clothes, smiting the breast, cutting off the hair and beard, lying on the ground, walking barefoot, and abstaining from washing and anointing themselves. Among the Greeks, the period was 30 days, except in Sparta, where it was limited to 10. The relatives of the deceased secluded themselves from the public eye, wore a coarse black dress, and in ancient times cut off their hair as a sign of grief. Among the Romans, the colour of mourning for both sexes was black or darkblue under the republic. Under the empire, the women wore white, black continuing to be the colour for men, who did not cut off the hair or beard as in Greece. Men wore their mourning only a few days; women a year, when for a husband or parent. The time of mourning was often shortened by a victory or other happy public event, the birth of a child, or the occurrence of a family festival. A public calamity, such as a defeat, or the death of an emperor or person of note, occasioned a public mourning, which involved a total cessation of business, called Justitium. In modern Europe, the ordinary colour for mourning is black; in Turkey, violet; in China, white; in Egypt, yellow; in Ethiopia, brown. It was white in Spain until 1498. Mourning is worn of different depth, and for different periods of time, according to the nearness of relationship of the deceased. On the death of a sovereign or member of the reigning house, a court mourning is ordered; and in this country, it is usual at the same time to recommend the adoption of a general mourning.

In Scotch Law, if a husband die, whether solvent or insolvent, the widow will be entitled to a prefer able payment out of the assets for mournings suitable to his rank. And the same privilege applies to mournings for such of the children as are to assist at the funeral. In England, there is no such privilege or distinction.

It is evident that in the last two classes the parallel ridges were produced at the same time. Elie de Beaumont has generalised this, maintaining that all parallel ridges or fissures are synchronous; MOUSE (Mus), a genus of rodent mammalia and on this he based a system of mountain-structure, of the family Muride (q. v.), having three simple which is too universal and too geometrical to be molar teeth in each jaw, with tuberculated sumtrue. The synchronism of parallel fissures had been mits, the upper incisors wedge-shaped, the lower noticed by Werner, and it is now received as a first compressed and pointed, the fore-feet with four principle in mining. The converse is also held to be tocs and a rudimentary thumb, the hind-feet fivegenerally true, that fissures differing in direction toed; the tail long, nearly destitute of hair, and differ also in age; yet divergence from centre, scaly. This genus includes Rats (q. v.) and mice; and consequent want of parallelism, as in the case the smaller species bearing the latter name.-The

MOUSE-EAR CHICKWEED-MOUTH.

COMMON M. (M. musculus) is perhaps not originally the ears not large. This species is not uncommon British, although now so abundant everywhere. It in some parts of the south of England; it is also accompanies man wherever he goes, and readily found in the south of Scotland, although less colonises every region, arctic, temperate, or tropical; frequently. It makes its nest among the stalks of its great fecundity, common also to most of its wheat, reeds, or other grasses, weaving together the congeners, causing means to be employed every leaves and panicles of grasses, the leaves being for where for the prevention of its excessive multipli- this purpose cut into shreds by its teeth. The nest cation. Aristotle made the experiment of placing is a very curious structure formed by mere intera pregnant female M. in a closed vessel filled with twining, without cement of any kind. It is genegrain, and found in a short time no fewer than 120 rally suspended among the stalks. It is globular, mice in the vessel. Of cats and mouse-traps it or nearly so, and entrance to it is through an seems unnecessary here to speak, and equally unne- opening, which almost completely closes up again. cessary to give a description of the common mouse. A still smaller species of M. (M. pumilus) is found There are several varieties of this species. That in the south of Europe.-An American species, the generally found in houses is smaller, and not so WHITE-FOOTED M. (M. leucopus), common in most dark in colour, as that common in barns and farm- parts of North America, and intermediate in its yards. A white variety sometimes occurs, and has habits between the Common M. and the Field M., been perpetuated in a half-domesticated state. The is said to depart from houses whenever either common brown kind is, however, at least as easily the cat or the brown rat appears in them.-The tamed, and readily becomes familiar enough. A Barbary M. (M. Barbarus) approaches in size to pied variety is not uncommon in India. Much the rats, and is distinguished by its longitudinally has been written about the singing powers of the striped fur. M.; it being asserted, on the one hand, that mice not unfrequently shew a strong love for music, and a power of imitating the song of birds; whilst, on the other hand, it is alleged that the singing of mice is merely the consequence of throat disease.The M. makes a nest like that of a bird in the wainscot of a wall, among the chaff or feathers of a bed, or in any similar situation. The litter is generally from six to ten in number. The WOOD M., or LONG-TAILED FIELD M. (M. sylvaticus), is a little larger than the Common Mouse. Its tail is

The name M. is often popularly given to animals considerably different from the true mice, as the Voles (q. v.).

MOUSE-EAR CHICKWEED (Cerastium), a genus of plants of the natural order Caryophyllaceae, having five sepals, five bifid petals, ten stamens, five styles, and a capsule bursting at the top with ten teeth. The species are numerous, natives of temSome of them are among the most common weeds perate and cold countries in all parts of the world. in Britain; others, having larger flowers, are occasionally planted in flower-borders and on rockworks. The form and hairiness of the leaves of some of the British species have given rise to the popular name.

MOUTH, DISEASES OF THE, occur in different forms, but usually begin with inflammation of the mucous membrane. The inflammation may be equally diffused, or may be chiefly or entirely confined to the mucous follicles. When diffused, it may either present no peculiar secreted product, or the surface may be covered with a curd-like secretion, or with patches of false membrane. It may further be attended with eruption, ulceration, or gangrene, any one of which may impress a special character on the disease, or it may present peculiarities from the nature of its exciting cause, as when it accompanies scurvy, or is the result of mercurial

action.

The following are the principal forms of inflam mation of the mouth, or stomatitis (Gr. stoma, the mouth), as it is termed by nosologists. 1. Common Diffused Inflammation, which appears in reddened, somewhat elevated patches, and sometimes occupies

Long-tailed Field Mouse (Mus sylvaticus) and Harvest large portions of the surface of the mouth. It is more

longer; its ears are also longer; its muzzle rather longer; its under-parts lighter in colour, than in the common mouse. It is abundant throughout Britain and the temperate parts of Europe, and is a grievous pest in gardens and fields. It lays up stores of grain and other food, either in thick tufts of grass, or just under the surface of the earth. The quantity of food laid up in such stores is often wonderfully large. The Field M. is timid, gentle, and easily tamed.-The smallest British M., and the smallest British quadruped, is the HARVEST M. (M. messorius), of which the head and body are only 24 inches in length, the tail being almost equally long, and to some degree prehensile; the general form elongated and slender, the head narrow,

commonly a complication of other diseases than an original affection. When of the latter character, it is generally caused by the direct action of irritants, as by scalding drinks, corrosive substances introduced into the mouth, accumulated tartar on the necks of the teeth, &c. In ordinary cases, cooling and demulcent liquids (such as cream or almond oil) applied locally, an occasional saline cathartic, with a soft and chiefly farinaceous diet, constitute the whole of the necessary treatment.

2. Diffused Inflammation, with curd-like exudation, is almost entirely confined to infants, and is described under its popular name of THRUSH.

3. Inflammation of the Follicles, and Eruption or Vesicular Inflammation, are described in the article APTHE (q. v.).

4. In Ulcerative Inflammation, Cancrum Oris, or Canker, an ulceration often of considerable si

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MOZARABIAN LITURGY-MSKET.