M U S M U S 109 consists of a thick soft under-fur, interspersed with longer stiff, glistening hairs, which overlie and conceal the former, on the upper surface and sides of the body. The general colour is dark umber -brown, almost black on the back and grey below. The tail and naked parts of the feet are black. The musky odour from which it derives its name is due to the secretion of a large gland situated in the inguinal region, and present in both sexes. The Musk-rat is the only species of its genus and is peculiar to America, being extensively distributed in suit able localities in the northern part of the continent, extend- Musk-rat. ing from the Atlantic to the Pacific, and from the Rio Grande to the barren grounds bordering the Arctic Seas. It is aquatic in its habits, living on the shores of lakes and rivers, swimming and diving with great facility, feed ing on the roots, stems, and leaves of water-plants, or on fruits and vegetables which grow near the margin of the streams it inhabits. Musk-rats are most active at night, spending the greater part of the day concealed in their burrows dug out of the bank, consisting of a chamber with numerous passages, all of which open under the surface of the water. For winter quarters they build more elaborate houses of conical or dome-like form, composed of sedges, grasses, and similar materials plastered together with mud. As their fur is an important article of commerce, large numbers are annually killed, being either trapped or speared at the mouths of their holes. The name Musk-rat is applied in India to a large species of Shrew (Sorex cazrulcsccns or indicus) which frequents houses at night, hunting round rooms for cockroaches and other insects, occasion ally uttering a sharp shrill cry. The strong musky odour of the animal arises from large glands beneath the skin of the side of the body, a short distance behind the fore-limbs. This odour is so powerful and penetrating that it is popularly believed in India that if the animal runs over a corked bottle of wine or beer it will infect the fluid within. Jerdon says that certainly many bottles are met with quite undrinkable from the peculiar musky odour of their contents, but, rejecting the possibility of its passing through the glass, he attributes it to the corks having been infected pre viously to bottling, stating in corroboration of this view that he has never found the odour-in liquors bottled in England. MUSLIN, a term embracing the thin delicate woven cotton fabrics, the lightest and most airy of all textures. The word is derived from Mosul ; the original home of muslin-weaving is the East Indies, where even yet won derful fabrics for airy lightness and delicacy continue to be woven with the aid of only the most rude and primitive appliances. The most delicate muslins are made at Dacca, where webs have been woven of yarn calculated to be equal to 380 (that is, 380 hanks, each 840 yards in length, weigh 1 K>). Such a web measuring 10 yards 1 foot in length by 3 feet in breadth, and having 104 threads of warp and 100 of weft per inch, was found to weigh not more than 1565 grains. Figured, embroi dered, colour -woven, and printed muslins are made at various places, principally in Madras province, and gold and silver printed muslins are made at Jeypore and Hy derabad in India. The making of muslin in Europe was first attempted at Glasgow by Robert Monteith about the year 1780, but he had to procure Indian bird-nest yarn for his web. The improvements in machinery effected about that time, however, soon enabled spinners to produce yarn of high counts, and thereafter the muslin trade took firm hold in the west of Scotland. In recent times the perfection of combing machinery, <tc., has enabled spinners to supply yarn of much greater tenuity than has ever been spun in India, and indeed vastly finer than is of any use for weaving purposes. A few yards of muslin have been woven with 700 cotton, but it is of use only to indicate the limit up to which it is possible to Aveave yarn. Fine muslin or tarlatan has been woven of 440 yarn by M. Thivel Michon of Tarare in France, but to the eye and touch it is less fine and delicate than Dacca "mulmul khas," owing possibly to dressing with starch, and to the less degree of condensation in machine-spinning as compared with hand-spinning. The varieties of European muslins and their applications are numerous. Among plain mus lins are included hooks, mulls (from " mulmul "), jacconets, tarlatans, Bishop and Victoria lawns, nainsooks, etc., chiefly distinguished by variety of finish, dressing, folding, &c. For window-curtains, hangings, etc., there are manufactured harness and book muslins, lenos, sprigs, spots, and lappets ; and for ladies dresses plain, striped, and figured grenadines, and saccarillas, besides which dyed and printed muslins are largely used. Sewed muslin, which was formerly an important Scottish industry, also continues to be a branch of the trade. MUSSCHENBROEK, PIETKR VAx(1692-1761), natural philosopher, was born at Leyden in March 1692, and studied at the university of his native city. The teacher from whom he derived the most profit was the eminent mathematician Gravesande. A scientific partnership was formed in 1717 between the master and the pupil for the prosecution of natural philosophy according to the prin ciples of Newton, and in opposition to those of Descartes ; Gravesande concentrating his attention on the theoretical part of the study, while Musschenbroek conducted the experiments. The consequence was that the downfall of Cartesianism and the establishment of Newtonianism were very much accelerated in Holland. Graduating in 171 5 with a dissertation, De aeris prxsentia in humoribiis ani- malium, Musschenbroek was appointed professor at Duis- burg in 1719. In 1723 he was promoted to the chair of natural philosophy and mathematics at Utrecht. In 1731 he declined an invitation to Copenhagen, and was promoted in consequence to the chair of astronomy at Utrecht in 1732. The attempt of George II. of England in 1737 to attract him to the newly-established university of Gottingen was also unsuccessful. At length, however, the claims of his native city overcame his resolution to remain at Utrecht, and he took possession of the mathematical chair at Leyden in 1739, where, declining all offers from abroad, he con tinued till his death in September 1761. His first important production was Epitome clcmenlonnn physico- mathcmaticorum, 12mo, Leyden, 1726, a work which was after wards gradually altered as it passed through several editions, and which appeared at length (posthumously, edited by Ludolf) in 1762, under the title of Introductio ad philosophiam natural-em. The Physicsz experimental es et geometries?, dissertationcs (1729) threw new light on magnetism, capillary attraction, and the cohesion of bodies. A Latin edition with notes (1731) of the Italian work Safjgi di natura-li espcrioize fatte nclV Accadcmia del Cimcnto con tained amid many other curious investigations a description of a
