Page:The American Cyclopædia (1879) Volume X.djvu/590

 584 LOGWOOD LOIRE water. Its decoction assumes various colors, according to the time it has been prepared and the substances with which it is treated. It is first deep red, but becomes paler by absorb- ing oxygen, and at the same time it acquires the property of precipitating gelatine. Acids brighten the color, while they also make it paler ; alkalies render it of a purplish or vio- let hue, and the salts of iron dark violet blue. The wood is principally useful for furnishing red and blue, but more particularly black dyes. By the use of iron and alum bases they are obtained of various degrees of intensity, and with proper mordants are rendered permanent. The coloring principle of logwood was sepa- rated about the year 1811 by Chevreul, and this is now known by the name of haematoxy- line. He obtained it from the watery extract in transparent brownish yellow crystals, the composition of which when anhydrous is rep- resented by the formula C^HnOis. Erdmann Logwood. also procured 4 oz. of the crystals from 2 Ibs. of the pulverized extract by digesting it in 2 Ibs. of ether, with a portion of sand intermixed to prevent agglutination, and afterward expel- ling the ether by evaporation. Haematoxyline resembles liquorice root in taste, is soluble in boiling water, and with alcohol and ether pro- duces reddish yellow solutions. Besides this substance, the wood contains a great variety of salts of lime, alumina, iron, and manganese, together with a fatty or resinous substance, a volatile oil, tannin, acetic acid, &c. Logwood is used in medicine as well as in dyeing, being a mild astringent without irritating properties. It is given in extract or decoction in cases of chronic diarrhoea, chronic dysentery, and in the relaxed state of the bowels succeeding cholera infantum. It imparts its color to the alvine evacuations. A weak solution of the extract is very useful in staining anatomical preparations. To prepare the wood for use, the imported logs were formerly cut by machi- nery into chips by means of steel cutters upon a horizontal drum, against which they were moved endwise; but the practice is now to grind the wood to powder, in which state the infusion is more readily obtained than from the chips. Logwood was taken to Europe for a dyeing material soon after the discovery of America. Its introduction into England was violently opposed in the time of Queen Eliza- beth, and an act was passed prohibiting its use. This was repealed in 1661, when the demand for logwood rapidly increased. It was ob- tained only in the Spanish possessions ; and in order to procure it the New Englanders made settlements in Yucatan, and sent thence large quantities to the north and to Jamaica. The opposition of the Spaniards led at last to a special treaty between England and Spain, by which British subjects were permitted to cut and ship the wood in the bay of Campeachy ; whence the name it has received of Campeachy wood. In 1715 the tree was introduced into Jamaica ; by means of planting the seed and from being cultivated in plantations it spread all over the island. Thus Jamaica also has fur- nished large quantities to commerce. LOHER, Franz von, a German author, born in Paderborn, Oct. 15, 1818. In 1846-7 he vis- ited Canada and the United States, and in 1849 established the Westfdlisclie Zeitung at Pader- born. In 1855 he became professor in the university of Munich. His works include Des deutschen Vollces Bedeutung in der Weltge- schichte (Cincinnati, 1847) ; GescMchte und Zustdnde der Deutschen in Amerika (2d ed., Gottingen, 1854) ; the epic poem, General Spork (2d ed., Gottingen, 1856); Land und Leute der alten und neuen Welt (3 vols., 2d ed., 1860) ; Jakobaa von Bayern (2 vols., Nord- lingen, 1861-' 9) ; and Aus Natur und Ge- schichte vom Elsass-Lothringen (Leipsic, 1871). LOIR (anc. Lidtricu*), a river of France, which rises near the centre of the department of Eure-et-Loir, in a range of hills dividing its basin from that of the Seine, and joins the Sarthe a little above the junction of the latter with the Mayenne, 7 m. N. of Angers. Its length is 150 m., and it is navigable for 80 m. Its principal tributaries are the Ozane, Braye, Conie, Long, and Meaulne. LOIRE (anc. Liger a river of France, run- ning N., K W., and finally W. by S., across the central and western parts of the country, and dividing it into two nearly equal parts. It rises on the slope of the CeVennes, in the department of Ardeche, and passing by the towns of Le Puy, Nevers, Orleans, Blois, Am- boise, Tours, Saumur, and Nantes, flows into the Atlantic near St. Nazaire. Its princi- pal affluents are the Arroux, Nivre, Allier, Cher, Indre, Vienne, Mayenne, and Sevre- Nantaise. Below Nantes, where it first feels the influence of the tide, it is studded with small islands. Its length is upward of 600 m. ; it is navigable from its mouth to Koanne, a