stems; and _M. Watsoni_, another fine deciduous Japanese bush or small tree with very fragrant pure white flowers 5 to 6 in. across. [Illustration: _Magnolia grandiflora_, shoot with flower; rather less than ½ nat. size. 1. Flower after removal of the sepals and petals, showing the indefinite stamens, s, and carpels, c. 2. Fruit--the ripe carpels are splitting, exposing the seeds, some of which are suspended by the long funicle. 3. Floral diagram, b, bract.] The tulip tree, _Liriodendron tulipifera_, a native of North America, frequently cultivated in England, is also a member of the same family. It reaches a height of over 100 ft. in a native condition, and as much as 60 to 80 ft. in England. It resembles the plane tree somewhat in appearance, but is readily recognized by lobed leaves having the apical lobe truncated, and by its soft green and yellow tulip-like flowers--which however are rarely borne on trees under twenty years of age. For a description of the principal species of magnolia under cultivation see J. Weathers, _Practical Guide to Garden Plants_, pp. 174 seq., and for a detailed account of the American species see C. S. Sargent, _Silva of North America_, vol. i. MAGNUS, HEINRICH GUSTAV (1802-1870), German chemist and physicist, was born at Berlin on the 2nd of May 1802. His father was a wealthy merchant; and of his five brothers one, Eduard (1799-1872), became a celebrated painter. After studying at Berlin, he went to Stockholm to work under Berzelius, and later to Paris, where he studied for a while under Gay-Lussac and Thénard. In 1831 he returned to Berlin as lecturer on technology and physics at the university. As a teacher his success was rapid and extraordinary. His lucid style and the perfection of his experimental demonstrations drew to his lectures a crowd of enthusiastic scholars, on whom he impressed the importance of applied science by conducting them round the factories and workshops of the city; and he further found time to hold weekly "colloquies" on physical questions at his house with a small circle of young students. From 1827 to 1833 he was occupied mainly with chemical researches, which resulted in the discovery of the first of the platino-ammonium compounds ("Magnus's green salt" is PtCl2, 2NH3), of sulphovinic, ethionic and isethionic acids and their salts, and, in conjunction with C. F. Ammermüller, of periodic acid. Among other subjects at which he subsequently worked were the absorption of gases in blood (1837-1845), the expansion of gases by heat (1841-1844), the vapour pressures of water and various solutions (1844-1854), thermo-electricity (1851), electrolysis (1856), induction of currents (1858-1861), conduction of heat in gases (1860), and polarization of heat (1866-1868). From 1861 onwards he devoted much attention to the question of diathermancy in gases and vapours, especially to the behaviour in this respect of dry and moist air, and to