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LEFT LEADVILLE 436 LEAGUE OF NATIONS in cubic or octahedral crystals; sp. gr. 11.38. The lead of commerce is often nearly pure and can be obtained perfectly so by reduction of the pure nitrate. Metallic lead, exposed to the ac- tion of air and pure water, is powerfully corroded, and as a result the water is found to have dissolved the oxide of lead. The impurities of most waters modify this tendency by forming a thin film on the surface of the metal and so prevent- ing any further oxidation. As a sani- tary precaution, slate cisterns are great- ly to be preferred to leaden ones. Lead enters into the composition of type-metal, pewter, Britannia metal, and plumbers' solder. The best tests for lead are hyd- ric sulphide, which forms a black sul- phide, and potassic chromate, which gives a yellow precipitate of lead chromate. LEADVILLE, a city and county-seat of Lake co.. Col.; on the Colorado and Southern railway, the Denver and Rio Grande, and the Colorado Midland rail- road; 80 miles S. W. of Denver, the State capital. Leadville is one of the most important localities in the world for the mining and reduction of the ores of the precious metals, some of the mines being 700 feet deep. It is the mining, farming and grazing trade center for an extensive region; contains a court house, jail, hospital, and almshouse; has rich deposits of gold, silver and lead, large sampling, refining and reduction works, smelting furnaces, etc. The city is lighted by electricity and gas; has an excellent water supply, well organized fire and police departments, daily and weekly periodicals, National banks. Pop. U910) 7,508; (1920) 4,959. ^ LEAF, in botany, a flat expansion di- visible into two similar portions, often halves, by a vertical plane running through the apex and point of insertion. The under or outer surface generally differs from the upper or inner in color, structure, and in the nature and appendages of the epidermis. On the lower part of the stem or base of a shoot are the scale-leaves or phyllades; above these are the ordinary foliage leaves, and above these again, below the flowers, are the bracts. The foliage leaves are the chief organs of assimila- tion, and develop large quantities of chlorophyll, their form and appearance being very varied. The bracts are gen- erally smaller. The foliage leaves and calyx and corolla leaves become trans- formed into stamens, and these modified into carpels. A leaf is called also a phyllome. A leaf consists of two parts, a stalk, called the petiole, and an ex- panded surface termed the blade or 1am- 'ina. When the petiole is absent the leaf is said to be sessile. LEAF, WALTER, an English scholar; born in 1852. After a brilliant career at Cambridge University, where he was Senior Classic, Chancellor's Medalist, and Fellow of Trinity, he entered mercantile life in 1877, retiring in 1892. A founder of London Chamber of Commerce, Chair- man 1887; Pres. Hellenic Society 1914, and member of War Finance Committee same year. Litt.D. degrees from Ox- ford and Cambridge. Editor of the "Journal of Hellenic Studies," and pub- lished "The Story of Achilles" (1880), With J. H. Pratt; "The Iliad of Homer Translated Into English Prose" (1882), with A. Lang and E. Myers; "The Iliad" (1886-1888); "Companion to the Iliad" (1892); "Troy" (1912); "Homer and History" (1915), etc. LEAGUE, a combination or union be- tween two or more persons for the pro- motion of mutual or common interests, or for the execution of any design in com- mon. Also a treaty, alliance, or confed- eration between two or more sovereigns or governments for mutual aid and de- fense. An offensive league or alliance is when two or more states agree to unite in attacking a common enemy; a defen- sive league is when the contracting par- ties agree to assist each other in their defense against a common enemy. LEAGUE OF NATIONS. While this ideal has been in the mind of many mod- ern thinkers on international law and while many statesmen have furthered the idea it first became a matter of prac- tical statesmanship through the influence of President Wilson. In his famous ad- dress, Jan. 8, 1918, he gave as the last of his celebrated fourteen bases of the com- ing peace: — "A general association of nations must be formed under specific covenants for the purpose of affording mutual guarantees of political and ter- ritorial independencies for great and small states alike." Later in the year, at the Independence Day celebration at Mt. Vernon, the President said one of the ends to which the United States entered the war was: "The establishment of an organization of peace which shall make it certain that the combined power of free nations will check every invasion of right and serve to make peace and jus- tice the more secure by affording a defi- nite tribunal of opinion to which all must submit." Finally on Sept. 27, 1918, he again reiterated that the League of Na- tions would play an important part in the peace settlement, in fact he declared it to be an "indispensable instrumen- tality" if the coming peace settlement