the river Frigidus, nortli of Aquileia, killed himself.
ARBOLEDA, är'bṓ-lā'Dȧ, Julio (1817-62). A Colombian poet and political leader. He
was born at Barbacoas and was educated in
Europe. In 1856 he joined the Conservative
revolt in Antioquia, and soon became the leader
of his faction. He concluded an alliance with
President Moreno, of Ecuador, and made war
upon the Federalist dictator, Mosquera. With
the support of the States of western Colombia,
he assumed supreme power, but soon afterwards
was assassinated. In a literary way he is
chiefly known for his poems, which, including
Dios y la virtud, Estoy en la cárcel, and Mo aussento, gave him high rank among Spanish-American poets. The manuscript of his most important work, Gonzalo de Oyón, was almost completely destroyed by an enemy, and only fragmentary copies are preserved.
AR'BOR DAY (Lat. arbor, tree). A day set
apart by the legislatures of most of the States
and Territories of the United States for the
annual planting of trees by the people, and
more especially by the school children. B. G.
Korthrop, while secretary of the Connecticut
Board of Education, seems to have been the
first — in 1865 — to suggest the annual planting
of trees under the direction .of a State govern-
ment. J. Sterling Morton was probably the
first, however, to propose the setting apart of
a certain day annually for the purpose, and in
1872, largely" through I'lis effoi'ts, the custom was
instituted in Nebraska. At present Arbor Day
is observed in nearly every State and Territory;
in some as a legal holiday, in others as a school
holiday. In addition, several States, including
New York, publish an Arbor Day manual. The
exact date is not uniform throughout the coun-
try, though it generally falls late in April or
early in May.
ARBOR DIA'NÆ (Lat., tree of Diana, the alchemic name of silver). An arborescent pre- cipitate of metallic silver from a solution of silver nitrate, produced by the addition of a metallic element such as mercury. The pro- portions recommended are as follows: Dissolve twenty grains silver nitrate in one fluid ounce of water in a convenient bottle, add one-half dram of pure mercury, suspend a jjieee of zinc by means of a fine thread secured to the cork, and in a day or two the arborescent appearance will present itself.
AR'BORE'TUM (Lot., from arlor, a tree I. A collection of specimen trees in a park or nurs- ery. See Botanic Gardens; Forestry: Horticulture; Nursery.
AR'BORICUL'TURE (Lat. arhor. tree +
cultura, care, cultivation). A term referring to
the scientific cultivation of trees. It embraces
that part of horticulture which treats of the
planting and cultivation of ornamental and fruit
trees, and that part of forestry known as sylvi-
culture. The horticultural growing of various
trees is discussed under the corresponding sjiecial
licadings. Forest practices are described under
FORESTRV.
AR'BOR VITÆ (Lat.. tree of life), Thuja. A genus of plants of the order Coni-ferse, allied to the cypress, and consisting of evergreen trees and shrubs with compressed or flattened branchlets — small, scale-like, imbricated leaves. Species of arbor vit* arc found in the north temperate zones of both hemispheres. The common arbor vita? {Thuja occidciitalis) is a native of North America, especially between latitude 45° and latitude 49°, but has long been well known in Europe. It is a tree forty to fifty feet high; its branches are horizontally ex- panded, and the strobiles (cones) small and obovate. The young leafy twigs have a balsamic smell, and both they and the wood were for- merly in great repute as a medicine; the oil obtained by distillation from the twigs, which has a pungent and camphor-like taste, has been recommended as a vermifuge. The wood of the stem is reddish, soft, and very light, but com- pact, tough, and durable, bearing exposure to the -weather remarkably well. The tree is com- mon in Great Britain, jjlanted chiefly as an ornament. It seldom attains so great a size as in its native country. It flourishes in cool, moist localities. The Chinese arbor vitie. Thuja orientalis, a native of China and .lapan, which is inunediately distinguishable from the former species by its upright branches and larger, al- most globose and rough strobiles, is also, in Great Britain and upon the continent of Europe, a common ornament of pleasure grounds; but it does not attain so great a size as the preced- ing, and is more sensible of the cold of severe winters. The balsamic smell is very agree- able. The tree j'ields a resin with a pleasant odor, to which medicinal virtues were once ascribed: hence the name, arhor riiw, given to this species and extended to the genus. There are several other species of Thuja, some of which seem well suited to the open air in the climate of Great Britain, and others require the protec- tion of greenhouses. Among the former are- Thuja plicata. California to Alaska, and Thuja dolahrata. a native of Japan, a tree of great height and thickness, which will not im- probably prove one of the most important of the whole genus. In favorable forest con- ditions both Thuja occidentalis and Thuja plicata become rather large trees, the timber of which is very valuable. There are about sixty horticultural varieties of the American species, that vary in habit of growth, color of foliage, or other characteristics. Slany of these are popular in landscape gardening. A tree com- mon in North America and there known by the name of White Cedar is sometimes included in the genus Thuja, under the name of Thuja sphwroidea, but is more generally ranked in the genus Cupressus as Cupressus thyoides. See Cypress. Closely allied to the genus Thuja is Callitris. See Saxdarac.
Fos.sii. Forms. The genus Thuja, like many other forms of conifers, is represented by an- cestral forms in Cretaceous rocks of northern Europe, and with the advance of time is found to migrate from northerly to more soutlierly regions, till during Pliocene time it disappeared from Europe. Thuja is also known in the Jliocenc lipcls of Dakota.
ARBROATH, är-brōTH' (Celt. aber confluence, mouth + Brothock), Aberbrothwick, ăb'ẽr-brŏth'ĭk, or Aberbrothock, -ŭk. A seaport town in Forfarshire, Scotland, on the North Sea, about seventeen miles east-northeast of Dundee (Map: Scotland, F 3). Here King William the Lion founded a Tyronensian abbey in honor of Thomas à Becket
