BITUMEN. 
May and June.—The other species at present 
grown most commonly in gardens are those de- 
sisnated luteus, albus, vernus, varius, and lathy- 
roudes. 
BITUMEN. Another name for asphalt; but 
the term d%twmen may rather be employed gener- 
ically to denote the compounds of carbon and 
hydrogen with or without oxygen, existing in 
asphalt, petroleum, coal, &c., so that the terms 
bituminous slate, coal, &c., are properly employed, 
although their constituents are combined in vary- 
ing proportions. For the chemical characters 
refer to AspHaLT, Perroneum. Bituminous sub- 
stances are, amber, asphalt, berengelite, coal, 
elastic bitumen, fossil copal, guayaquillite, har- 
tite, hatchetine, idrialin, ixolyte, middletonite, 
ozokerite, petroleum, retinasphalt, and rock tar. 
Asphalt enters into the composition of some, 
black varnishes, and rock-tar boiled to a certain 
consistency may be employed alone while hot, 
especially if some resin be fused with it. Bitu- 
minous mastic, or asphalt, has been extensively 
employed in France, and has received some at- 
tention for covering roofs, pavements, floors, and 
lining cisterns. A bituminous limestone is ground 
and.added to one-fifth of its weight of asphaltum, 
fused in an iron kettle, and when sufficiently 
homogeneous it is spread over the surface to be 
covered. A mixture of coarse and fine pebbles, 
fragments of brick, stone, &c., are often intro- 
duced into the mass for pavements. Coal -tar 
yielding by evaporation a pitch resembling as- 
phalt, but more brittle when cold, may be em- 
ployed as a substitute for asphalt, mixed with 
lime, pounded brick, and stones. When asphalt 
is employed for the floor of a hall, or entrance, 
to which it is well adapted, it may be ornamented 
with any device by impressing in its surface 
while hot small peebles of the same or different 
colours. 
BITUMINOUS SHALE. Slates impregnated 
with bitumen, which is sometimes so abundant 
that they may be employed as fuel. The slates 
containing iron pyrites are also employed in the 
manufacture of alum. The bituminous impreg- 
nation of the copper-slate of Germany allows it 
to be treated metallurgically for copper, notwith- 
standing its small content of copper-pyrites. 
BIXA. See Annorra. 
BLACK. A colour caused by the refraction of 
all the rays of light. When all the rays are pre- 
sent or reflected, the effect is whiteness; and 
when all are absent or refracted, the effect is 
blackness.—A black colour in horses, especially 
a glossy jet black, well marked, and without 
much intermixture of white, is highly esteemed. 
Any considerable proportion of white, especially 
when it spreads round the eyes, or a great way 
up the legs, adds nothing to either goodness or 
beauty. The black horses of Hngland have 
usually more white than the black horses of any 
other country, particularly those of Denmark, 
Holland, Spain, and Arabia. Yet a star or blaze 
BLACKCAP. 
437 
of white, or a white muzzle, or a tipping of one 
or more of the feet with white, always looks well 
and lively, and is regarded by some persons as 
an indication that the animal is better tempered 
than if he were wholly black. Some blackish 
horses have brown muzzles and brownish flanks, 
and are often called black browns; some have a 
lighter colour about the muzzle, and are called 
mealy-mouthed ; and some have a white circle 
round their eyes, and sometimes more or less 
white upon the hips, and are called pigeon-eyed. 
Blackish horses which partake most of the brown 
admixture, are generally the strongest in consti- 
tution. 
BLACK BENT. See Anorrcurts. 
BLACKBERRY. See Currant and BRamBre. 
BLACK BINDWEED. See Binpweep. 
BLACKBIRD,—scientifically Merula vulgaris. 
A well known singing-bird, of the merulide or 
thrush family. The male with his yellow bill, 
and jet black plumage, is so universally known 
in Britain as not to need description. The female 
has blackish brown bill and legs, brownish-black 
plumage above, and umber-brown plumage on 
the breast, the margin of each feather passing 
into greyish-white. The young have similar 
colours to those of the female; and the males 
acquire their yellow bill and jet black plumage 
only after the second moult. Albine blackbirds, 
or varieties of white and cream colours, are some- 
times seen. 
The blackbird is generally but not always shy. 
It frequents hedges, thickets, shrubberies, and 
large gardens, feeds on slugs, shell-snails, insects, 
pease, currants, and cherries, and, when surprised 
or disturbed, utters a sharp cry of alarm, and 
escapes to the shelter of the nearest dense foliage. 
It often makes much havoc in a garden, but it 
compensates for this, not alone by its rich song, 
but by its destruction of snails and slugs.—The 
blackbird begins early in spring to build its nest, | 
and usually selects for it a thickset hedge, an 
isolated close bush, a low ivied tree, or any simi- 
lar situation. It builds with mosses, root fibres, 
and small sticks, lays on an interior coat of mud 
plaster, and finishes with a lining of fine dry 
grass. The eggs are four or five in number, of a 
bluish green, variegated with darker tints; and 
two or sometimes three broods are hatched dur- 
ing the spring and summer. _ 
BLACK CANKER. See Turnip-F ty. 
BLACKCAP, — scientifically Curruca atrica- 
pula. A singing bird, of the sylviadz or warbler 
family. It occurs throughout the most of Europe, 
particularly in the northern and eastern districts ; 
and it arrives in Britain about the middle of 
April, and leaves about the end of September. It 
is inferior only to the nightingale in the richness 
of its melody, and is popularly called the mock 
nightingale in Norfolk and other parts of Britain. 
The male is nearly six inches in length, and about 
41 drachms in weight. His bill is brown; his 
irides, dark hazel; the upper part of his head, 
