fine kind of cotton cloth, with a downy nap on its surface. The name is said to be derived from Mosul in Asia, where it was originally manufactured. It was first imported into England from India in 1670, and is now manufactured in immense quantities both in Britain and on the Continent, rivalling in quality, and surpassing in cheapness, the finest products of the eastern looms. (See Cotton, and Cotton Manufacture.)

Musonius, Caius Rufus, a Stoic philosopher, was the son of a Roman knight, and was born at Volsinii (Bol-sena) in Etruria about the beginning of the first century. He early became a disciple of the doctrines of the Porch. But his maxims, as quoted by Stobaeus, A. Gellius, and others, have a more direct reference to practical than to speculative ethics. Since the ills of life are essentially paltry, he held that they ought to be met by quiet resignation, not avoided by suicide. The cultivation of the virtues of austerity, disinterestedness, chastity, and temperance, is the sure and the only means of securing happiness. "Everywhere," said he, "one can be happy, for everywhere one can be virtuous." The happiness of man is thus lodged within himself. It is not therefore necessary that we should defend ourselves from the injuries of others by inflicting retribution in return. The best way to make our fellows respect us is to respect ourselves. Such an elevated tone of morality was not palatable to the depraved court of Nero. Musonius accordingly fell into disgrace. Under the pretext of having been privy to the famous conspiracy of Piso against the emperor, he was banished to the isle of Gyaros (Ghiouro) A.D. 66. He appears to have returned on the accession of Galba in 68; and he is found shortly afterwards among the deputies who were sent by the Emperor Vitellius to Antonius Primus, the victorious general of Vespasian. Yet he subsequently rose high in the favour of Musschenbroek.

Vespasian, so that he was allowed to remain in the city when all the other Stoics were driven into banishment for their intolerant precepts. The date of his death is unknown. The extant fragments of his works have been collected and published by Peerlkamp, under the title of C. Musonii Ruth Religie et Apophthegmata, Svo, Haarlem, 1822.

Musschenbroek, Peter van, an eminent natural philosopher, was born at Leyden in March 1692. Studying at the university of his native city, he became a proficient in classics under Perizonius and Gronovius, and in natural philosophy, chemistry, and medicine, under Seguerd, Bidloo, Le Clerc, Burman, Albinus, Boerhaave, and Rau. The teacher, however, 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 principles of Newton, and in opposition to those of Descartes. Gravesande concentrated his attention on the theoretical part of the study; Musschenbroek conducted the experiments; and both, by their separate investigations, corrected or confirmed the results obtained by each other. The consequence was, that the downfall of Cartesianism, and the establishment of Newtonianism, were very much accelerated in Holland. In increasing the knowledge, and in determining the future studies of Musschenbroek, the effect was also great. An inaugural dissertation which he delivered in 1718, on the occasion of taking his degree, brought out into full prominence his taste and talent for experimental science. It was entitled De Æris Presentia in Humoribus Animalium, and was full of experiments, carefully prosecuted and clearly explained. His fame was now established. He was appointed professor of natural philosophy and mathematics, and professor extraordinary of medicine in the university of Duisburg in 1719. In 1723 he was promoted to the chair of natural philosophy and mathematics at Utrecht. He was now placed in his proper sphere, and began to prosecute his favourite studies with increased vigour. His first important production was Epitome Elementorum Physici Mathematicorum, 12mo, Leyden, 1725—a work which was afterwards gradually altered as it passed through several editions, and which appeared at length in 1762, under the new title of Introductio ad Philosophiam Naturalem. The publication in 1729 of his next great work, Physica Experimentalis et Geometrica Dissertaties, raised his reputation to its acme. It threw new light on the subjects of the magnet, capillary attraction, and the cohesion of bodies. Scarcely less instrumental in advancing science was his Latin edition, in 1731, of the Italian work Saggi di Naturali Esperienze fatte nell' Accademia del Cimento. The numerous notes which he appended to this translation contained, amid many other curious investigations, a description of a new instrument, the pyrometer, which he had invented, and of several experiments which he had made on the expansion of bodies by heat. His great eminence was acknowledged in this same year by an invitation from the King of Denmark to Copenhagen. He declined this honour, 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 Göttingen 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. Here he resolved permanently to settle. Offers of preferment from Berlin, Madrid, and St Petersburg, were tendered to him in quick succession; yet, declining all these honours, he continued peacefully to instruct his pupils, and to pursue his favourite investigations till the day of his death in September 1761.

Musschenbroek is also the author of Elementa Physica