M O T M T the principal source of the commercial product. The Meleagrina margaritifera is a native of tropical seas, and is found around the coasts of all the lands within the tropics. The shells vary in size, the largest reaching to about the dimensions of a dessert plate, with a weight of from 1 to 1| R>. They also vary in colour to a consider able extent, some being dark and smoky round the outer edge with little iridescence, others dark but possessing a rich play of colours, and the greater part pearly white with varying iridescence. The principal sources of supply are the islands of the East Indian archipelago, the Pacific islands, the north-west Australian coast, the Persian and Ked Seas, and the Gulf of Panama. The largest and steadiest consumption of mother-of-pearl is in the button trade, and much is also consumed by cutlers for handles of fruit and dessert knives and forks, pocket-knives, &c. It is also used in the inlaying of Japanese and Chinese lacquers, European lacquered papier-mache work, trays, &c., and as an ornamental inlay generally. In an innumerable variety of small and fancy articles mother-of-pearl is also employed, its use being limited only by the moderate dimensions and thickness of material obtainable, and its rather brittle nature. The carving of pilgrim shells and the elaboration of crucifixes and ornamental work in mother-of-pearl is a distinctive industry of the monks and other inhabitants of Bethlehem. Among the South Sea Islands the shell is largely fashioned into fishing -hooks, a purpose for which its brilliant conspicuous appearance appears to render it suitable without the addition of any bait or other lure. Among shells other than those of Meleagrina margaritifera used as mother-of-pearl may be mentioned the Green Ear or Ormer shell (Haliotis tubercu- lat(i) and several other species of Haliotis, besides various species of Turbo. The pearl - shell fishery is an important industry on the north and north-west coasts of Australia, producing about 800 tons yearly, valued at over 100,000, the Papuan islanders of Torres Straits being employed as divers under European supervision, with skilled appliances. The shell of the golden-tipped variety of Avicula found here is much more valuable than the dark-edged one of the South Seas. The value of the fisheries depends much more on the shell than on the occasional pearls found, which indeed are sometimes, along with the "fish," a perquisite of the diver; but on the west coast, about Shark s Bay, a smaller variety of the same mollusc pro duces valuable pearls, their exciting cause being possibly present there in greater abundance. That the pearl itself is not due to disease, or to the presence of any irritating cause, seems clear from the fact that the mollusc can reject it at will, and often does so when taken (for which reason the diver, in seizing him, at once places his hand over the opening so as to close the shell) ; but it is believed now that the pearl is secreted and held ready to be dissolved by the powerful acid of the sac, and spread in nacreous layers over the spot irritated by the borer (Pholnx sp. ). Accordingly pearls are seldom found in the young "fish," whose shells are much harder outside, and not susceptible to such attacks. A mass of nacreous layers formed round a point of irritation or "blister" can some times be cut out of the shell, and might easily be mistaken for (and sold as) a pearl, but it is never quite perfect all round and is always hollow. Sometimes, after having secured the loose pearls, the fisher men deposit the mollusc again, unharmed, in a secure and accessible locality, and repeat the process for three and four years successively. MOTHERWELL, a police burgh of Lanarkshire, Scot land, is situated on the Caledonian Railway a short distance from the right bank of the Clyde, 2 miles north-east of Hamil ton and 1 1 east-south-east of Glasgow. The village, which takes its name from an old well dedicated to the Virgin, contained only 900 inhabitants in 1851, and owes its rapid increase to the coal and iron mines in the neighbour hood. It possesses one of the largest ironworks in Scotland, and also extensive engineering works. Motherwell was erected into a police burgh in 1865. The population in 1871 was 5746, and in 1881 it was 12,904. MOTHERWELL, WILLIAM (1797-1835), poet, anti quary, and journalist, born in 1797, rendered service in the collection of fugitive border poetry and wrote one or two very touching songs in the Scotch dialect, dying before he had fulfilled the promise of his earlier work. His short life was diversified by few incidents. The son of an iron monger in Glasgow, he was educated partly in Edinburgh and partly in Paisley. At the age of fifteen he was apprenticed in the office of the sheriff-clerk at Paisley, and appointed sheriff-clerk depute there in 1819. The impulse given by Scott to the pursuit of local ballads was still strongly in force, and the young law apprentice spent his leisure in collecting materials for a volume which he published in 1819 under the title of The Harp of Renfreivshire. In the course of the next eight years he extended his studies in the same field and published the results in 1827 in Min strelsy Ancient and Modern, prefaced by a very thorough historical introduction. Meantime he made a reputation by casual poems in newspapers and magazines, of which Jeanie Morrison, My Heid is like to break, and Wearie s Cauld Well have taken a fixed place in Scotch literature. These poems are his best work, but he gave most of the energy of his vigorous intellect to writing ballads and songs in English ; and he interpreted the martial spirit of the Norse sea-rovers with an enthusiasm and force which one would not expect from the plaintive character of his Scotch poems. His critical power and his learning were probably too great for his executive faculty ; but, what ever may be thought of his promise as a poet, it was un doubtedly quenched by his entrance into journalism and the fatiguing work of newspaper editing. He became editor of the Paisley Advertiser in 1828, of the Glasgow Courier in 1830, and died suddenly of apoplexy in 1835. A trying examination before a Parliamentary Committee was thought to have hastened his end ; but Conservative journalism at the time of the Reform Bill was exciting and uphill work, and it is a fair inference from the sad tone of some of his later poems that a baffled longing to achieve enduring fame added to the poet s worries and increased the strain on his constitution. A small volume of his poems was published in 1832, and a larger volume with a memoir in 1849. MOTHS. See BUTTERFLIES. MOTLEY, JOHN LOTHROP (1814-1877), the well-known historian of the Dutch Republic, was born on 15th April 1814 at Dorchester, now a part of Boston, Massachusetts, and from 1827 was educated at Harvard, where he graduated in 1831. He then studied for two years at Gottingen and Berlin, and after a period of European travel, chiefly in Italy, returned to America in 1834, where he became a student of law, and ultimately was called to the bar. In 1837 he married, and two years afterwards he published anonymously his earliest literary work, a two - volume novel, entitled Morton s Hope, or the Memoirs of a Young Provincial, which attained, and indeed deserved, only a moderate success. In 1841 he received his first diplomatic appointment, being made secretary of legation to the Russian mission, but, finding the atmosphere of St Peters burg uncongenial, he resigned his post within a few months and definitely resolved on a literary career. Besides con tributing various historical and critical essays to the North American Review, he published in 1849, again anonymously, a second novel entitled Merry Mount, a Romance of the Massachusetts Colony. About the year 1846 the project of writing a history of Holland had begun to take shape in his mind, and he had already prepared a considerable quantity of MS., when, finding the materials at his dis posal in the United States quite inadequate for the com pletion of his work, he resolved to migrate to Europe along with his family in 1851. The next five years were spent at Berlin, Dresden, Brussels, and the Hague in laborious investigation of the archives preserved in those capitals, and resulted in 1856 in the publication of The Rise of
