Page:Encyclopædia Britannica, Ninth Edition, v. 12.djvu/218

to have made mention of the horse-chestnut. Clusius (Rariorum plantarum hist., lib. i. p. 8, 1601) describes it as a vegetable curiosity, of which in 1588 he had left in Vienna a living specimen, but of which he had not yet seen either the flowers or recent fruit. The dry fruit, he says, had frequently been brought from Constantinople into Europe. The tree grows rapidly ; it flourishes best in a sandy, somewhat moist loam, and attains a height of 50 to 60 or more feet, assuming a pyramidal outline. Its boughs are strong and spreading. The buds, conspicuous for their size, are protected by a coat of a glutinous sub stance, which is impervious to water ; in spring this melts, and the bud-scales are then cast off . The leaves are com posed of 7 obovate-cuneate radiating leaflets (sec vol. iv. ]>. 112, fig. 115) ; when young they are downy and droop ing. From the early date of its leafing year by year, a horse-chestnut in the Tuileries is known as the " Marronnier du 20 Mars." The flowers of the liorse-chestnnt, which are white dashed with red and yellow, appear in May, aad sometimes, but quite exceptionally, again in autumn (Gard. Chron., 1868, p. 1116); they are very numerous on each rachis, and form a thyrse. Comparatively few of them afford mature fruit. The fruit is ripe in or shortly before the first week in October, when it falls to the ground, and the three-valved thorny capsule divides, dis closing tli3 brown and at first beautifully glossy seeds or nuts, having a resemblance to sweet chestnuts, and com monly three or else two in number. For propagation of the tree, the nuts may be sown either when fresh, or, if preserved in sand or eirth, in spring. Drying by ex posure to the air for a month has been found to prevent their germination. The cjtyledons do not rise to the surface of the soil. Rooks are wont to remove the nuts from the tree just before they fall, and to disperse them in various directions (R. Ellison, Benvickshire Naturalist, quoted in J. of Forestry, Apr. 1880, pp. 877, 878).

The bark of the horse-chestnut contains a greenish oil, resin, a yellow body, a tannin, C 26 H 24 Oj.,, existing likewise in the seeds and various parts of the tree, and decomposable into phloroglucin and crsciglyoxalic acid, C 7 H 6 3 , also cesculctin hydrate, and the crystalline fluorescent compound ccsciilin, of the formula C 2] H 24 13 (Rochleder and Schwar/:), with which occurs a similar substance frajcin, the paviin of Stokes (Q. J. Chcm. Soc., xi. 17, 1859 ; xii. 126, 1860), who suggests that its presence may perhaps account for the discrepancies in the analyses of resculin given by different authors. From the seeds have been obtained starch (about 14 per cent.), gum, mucilage, a non-drying oil, phosphoric acid, salts of calcium, saponin, by boiling which with dilute hydrochloric or sulphuric acid cesculic acid is obtained, quercitrin, present also in the fully developed leaves, cescigcnin, C 12 H 20 2 , and u:sculelin, C 9 H;0 4 , which is procurable also, but in small" quantity only, from the bark. Rochlederhas described as constituent principles of the cotyledons aphrodccscin, C 5 . 2 H 8 . 2 23 , a bitter glucoside, aryyrccscin, C 27 H 4 ,0 J2 , cescinic acid, C 24 H 40 O J2 , and querccscitrin, C 41 H 4(i 25 , found also in the leaves. To prepare pure starch from the seeds, Flandin (Compt. Rend., xxvii. 391, 1848 ; xxviii. 138, 1849) recommends kneading them, when peeled and bruised, in an aque ous solution of yjtf to -JV of their weight of sodium carbonate. E. Staffel (Ann. d. Cheat, u. Pharm., Ixxvi., 1850, p. 379) after dry ing found, in spring and autumn respectively, 10 9 and 3 38 per cent, of ash in the wood, 8 68 and 6 57 in the bark, and 7 68 and 7 52 in the leaves of the horse -chestniit. The ash of the unripe fruit contains 58 77, that of the ripe kernel 6T74, and that of the green shell 75 91 per cent, of potash (E. WollI ).

The wood of the horse-chestnut is soft, and serves only for the making of water-pipes, for turner s work and com mon carpentry, as a source of charcoal for gunpowder, and us fuel. Newly cut it weighs 60 ft, and dry 35 Ib per cubic foot approximately. The bark has been employed for dyeing yellow and for tanning, and was formerly in popular repute as a febrifuge and tonic. The powder of the dried nuts was at one time prescribed as a sternutatory in the Edinburgh Pharmacopoeia. It is stated to form with alum-water a size or cement highly offensive to vermin, and with two parts of wheaten flour the material for a strong bookbinder s paste. Infusion of horse-chestnuts is found to expel worms from soil, and soon to kill them if they are left in it (The Garden, xiii. 198, 1878). The nuts furthermore have been applied to the manufacture of an oil for burning, cosmetic preparations, and starch (v. stip.), and in Switzerland, France, and Ireland, when rasped or ground, to the bleaching of flax, hemp, silk, and wool In Geneva horse-chestnuts are largely consumed by graz ing stock, a single sheep receiving 2 ft crushed morning and evening. Given to cows in moderate quantity, they have been found to enhance both the yield and flavour of milk. Deer readily eat them, and, after a preliminary steeping in lime-water, pigs also. For poultry they should be used boiled, and mixed with other nourishment. The fallen leaves are relished by sheep and deer, and afford a good litter for flocks and herds.

One variety of the horse-chestnut has variegated leaves, and another double flowers. Darwin has observed that ^E. Pavia, L., the Red Buckeye of North America, exhibits a special tendency, under unfavourable conditions, to be double-blossomed (Anim. and PI., ii. 168). The seeds of this species are used to stupefy fish. The Scarlet-flowered Horse-chestnut, ^*. rubicunda, is a handsome tree, less in height, and having a rounder head than the common form. Another species, possessing flowers with the lower petals white with a red tinge, and the upper yellow and red with a white border, and fruit unarmed, is jE. indica. Among the North American species are the Foetid or Ohio Buckeye, jE. fflabra, Willd., and jE. flnva, Ait., the Sweet Buckeye. jE. calif ornica, Nutt., when full-grown and in flower, is a beautiful tree, but its leaves often fall before midsummer.

See Loudon, Arboretum, i. 147, 462 ; Gard. Chron., 1843, pp. 7, 737 ; 1878, i. 768, 828, and ii. 53 ; Technologist, 1865, p. 3 > Asa Gray, Man. ofBot., p. 117, 5th ed., 1872; Brewer and Watson, Gcol. Surv. Calif., "Bot."i. 106; Arboriculture, vol. ii. p. 319;. and, for the chemistry, Rochleder and Schwarz, Ann. d. Chem. u. Pharm., Ixxxvii. , 1853, p. 186, and Ixxxviii. 356 ; C. Zwenger, Ib., xc.,1854, p. 63; and Rochleder, Wicn. Akad. Sitzungsber.,l., 1860, xlv., 1862, xlviii., 1863, liv.-lvii., 1866-68.

(f. h. b.)

HORSE-MACKEREL is the name applied to a genus of fishes (Caranx) found in abundance in almost all tem perate and especially in tropical seas. The designation " cavalli," given to them by the early Portuguese navi gators, and often met with in the accounts of the adven tures of the buccaneers, is still in frequent use among the sailors of all nations. Some ninety different kinds are known, the majority being wholesome food, and some of the species attaining a length of 3 feet and more. The fish to which the name horse-mackerel is applied in Great Britain is Caranx tracfnirits, distinguished by having the lateral line in its whole length armed with large but narrow bony plates. Horse-mackerel are found singly on the coast all the year round, but sometimes they congregate in shoals of many thousands. Although well-flavoured, they are much more frequently used for bait than for food. This species has a most extraordinary range, being found almost everywhere within the temperate and tropical zones of the northern and southern hemispheres.

HORSEMANSHIP. See Horse, p. 195.

HORSENS, a seaport town of Denmark, in the province of Aarhuus and amt of Skanderborg, is situated at the head of the Horsens-fiord on the east coast of Jutland, and on the railway from Fridericia to Langaa, 25 miles south west of Aarhuus. It is a well-built town, and contains a Latin school and two market-places. In the neighbour hood there is a large prison. The town possesses a large foundry, machine shops, shipbuilding yards, lime -works, and manufactures of cloth and of woodwares ; it has also a good harbour. It is the birthplace of the navigator Vitus Bering or Behring, the discoverer of Behring Straits. The population in 1870 was 10,501.