chemical curiosity, but the metal forms several important alloys. It occurs in most iron-ores and pig-irons to some extent. A kind of pig-iron, called spiegeleisen, contains from 12 to 20 per cent, of manganese, and a metal much richer in manganese is called ferro-manganese. These alloys are used in the manufacture of Bessemer steel and other kinds of cheap steel, for without manganese these steels could not be worked. Manganese bronze, an alloy of copper and manganese, is valuable for certain purposes Manganese occurs chiefly as carbonate and as the black oxide. The latter is important in the manufacture of chlorine gas. An artificial manganese salt, potassium permanganate, is largely used in chemical processes. Manganese gives a violet tint to glass. Hence small quantities of manganese oxide are put into glass to neutralize the green color produced by the iron that is accidentally present.

Man'go, a fruit of the genus Mangifera, which contains 27 species of tropical Asiatic trees. M. Indica yields the common mango and is cultivated throughout the tropics. The fruit is kidney-shaped, four i-or five inches long, with smooth, pale green to reddish skin, and a seed almost as long as the fruit, which has a rough and fibrous shell. There is a strong suggestion of turpentine about the mango; usually a taste for the fruit has to be cultivated. It has been described as tasting like a "ball of cotton soaked in turpentine and molasses." In the tropics the mango is a staple article of food during the hot months, more than 130 varieties being cultivated in India alone. In some of the poorer varieties the pulp is full of fiber. The mango is extensively cultivated in the West Indies and more sparsely in southern Florida and California. The tree is an evergreen, grows from 30 to 40 feet high, and has a wealth of foliage.

Mangosteen (mn' g-stĕn), the fruit of a species of Garcinia (G. mangostana), a native of the East Indies. The mangosteen is one of the best, and is said to be one of the most luscious, of tropical fruits. It is about the size and shape of an orange, with thicker rind and similar pulpy segments. Its rind is purple outside, and the flavor is said to be something between a grape and a peach. It

Description images/pp0035 1


seems to be very difficult of cultivation except in the most favored situations. In the West Indies it is cultivated in Trinidad and 'Jamaica, but only in certain regions of these islands.

Man'grove, the ordinary name of species of Rhizophora, which number five or six and are widely distributed in the tropics. The commonest mangrove is R. mangle, and this is one of the most abundant plants of the swampy shores of tropical and subtropical seas. It is an important agent in the extension of land into the sea, by means of aerial roots which are put out from the branches and dangle in the wind until they reach the mucky soil beneath the water, where they strike root and become rigid. The seed also germinates while the fruit is still upon the tree, so that the young plantlets drop like plumb-bobs into the water and at once take root. In both of these ways the mangrove gradually advances seaward, and the detritus caught by the interwoven stems and roots presently builds up land. R. mangle grows along the western and eastern coasts of Florida, a round-topped bushy tree, the wood used for fuel and wharf-piles.

Manhattan Trade-School for Girls was founded in November, 190 2, in New York City, to afford industrial education for girls from 14 years to 17 or 18. The acknowledged need of American industry is such a substitute for the old plan of apprenticeship. In Manhattan Trade-School instruction is centered to a great degree about a few of the simple and useful tools, especially the needle, foot and electric power machines, the brush and pencil as used in drawing and coloring. About these tools centers a great number of industrial occupations. Domestic service is not taught, because the field is not sufficiently inviting to girls who possess the ambition for advanced industrial education. Health and physique are carefully guarded as indispensable to industrial efficiency. There is an attempt to provide a "trade-academic course" which shall secure an education to girls to back their technical training and make for an understanding of economic conditions and the essential relations of employers and employees. Actual orders are taken and filled at market-prices. Graduates of Manhattan Trade-School are easily placed, and have been retained when other employees are being retrenched. The school rapidly outgrew its equipment, and in 1906 removed to larger premises at 209 E. 23rd St., which already are fully crowded. Manhattan Trade-School is a private venture; but it seems probable that somewhat similar industrial high-schools will shortly be provided by New York City. Boston has imitated the school by Boston Trade-School, founded in 1904.

Manila (m-rVla), capital and chief town of the Philippine Islands, lies on a bay of Luzon, 650 miles southeast of Hong-Kong, with