I5LO 
B L U 
BOA 
235 
»ne, included in 4 berry-sh4ped calyx. 
'1 here are four species, viz. 
1. Blitum capitatum, with flowers in clus- 
tered heads at the joints and crown of tlie 
stalks, is a native of Spain and Portugal, but 
has been long preserved in the British gar- 
dens for the beauty of its fruit, ft is an an- 
nual plant, with leaves somewhat like those of 
the spinach ; the stalk rises two feet and a 
half high ; the upper part of the stalk has 
flowers coming out in small heads at even 
joint, and is terminated by a little cluster of 
the same ; after the flowers are past, the 
heads swell to the size of wood-strawberries, 
and when ripe have the same appearance, 
but are not eatable ; they are full of purple 
juice, which stains the hands of those who 
bruise them of a deep purple colour. 
2. Blitum tartaricum, with triangular 
acutely indented leaves, is a native of Tar- 
tary. It rises to near three feet high ; the 
flowers come out from the sides of the stalks, 
but are smaller than those of the capitatum, 
as is also the fruit. 
3. Blitum virgatum, with small heads 
growing from the sides of the stalks, is a 
native of the south of France and Italy. 
It seldom grows more than a foot high ; the 
leaves are of the same shape with those of 
the capitatum, but smaller. The flowers are 
produced at the wings of the leaves, almost 
the length of the stalk ; they are smaller, 
and not so deeply coloured as the first. 
4. Blitum chenopodioides, is a low plant, a 
native of Tartary. 
All these species being annual, must be 
propagated by seeds, and are very hardy. - 
BLOCKS, on ship-board, is the usual 
name for what we call pulleys at land. They 
are thick pieces of wood, some with three, 
four, or live shivers in them, through which 
all the running-ropes run. Blocks^ whether 
single or double, are distinguished and called 
by the names of the ropes they carry, and 
the uses they serve for. Double-blocks are 
used when there is occasion for much strength, 
because they will purchase with more ease 
than single blocks, though much slower. 
Block-and-block is a phrase signifying that 
two blocks meet, in haling any tackle or hal- 
liard, having such blocks belonging to them. 
Fish-block is hung in a notch at the end of 
the davit. It serves to hale up the flocks of 
the anchor at the ship’s prow. Snatch-block 
is a great block with -a shiver in it, and a 
notch cut through one of its checks, for the 
more readily receiving of any rope; as by 
tliis notch the middle part of a rope may be 
reeved into a block, without passing it end- 
wise. It is commonly fastened w ith a strap 
about the mainmast, close to the upper deck, 
and is chiefly used for the fall of the winding- 
tackle, which is reeved into this block, and 
then brought to the capstan. 
Blocks now used in the navy are made in 
the Portsmouth yard, by means of machine- 
ry, which has lately been erected for the 
purpose, and which performs the several ope- 
rations from the rough timber to the perfect 
block iu the completest manner possible. 
Block, engraving. See Engraving. 
BLOOD, sanguis, a red Honor circulating 
through the arteries, veins, and other vessels 
oi animal bodies ; and serving for the sup- 
port of life, and nourishment of all their parts. 
See Anatomy, and Physiology. 
BLOOM, a mass of iron after having un- 
dergone the first hammering, called biomary. 
BLOSSOM, denotes ti ie flowers of plants, 
but more especially of fruit-trees. 
BLOW-PIPE, or bloiving-pipe , a hollow 
tube, used by several artificers; as enamel- 
lers, glass-makers, jewellers, &c. it is a 
w ind instrument for the purpose of increasing 
the heat of a candle or lamp, as common 
bellows are employed for raising the tempe- 
rature of a fire or furnace. The blow-pipe 
is of great use in practical chemistry. See 
Chemistry. 
BLOW ING of glass, one of the methods 
of forming the divers kinds of works in the 
glass manufacture. 
It is performed by dipping the point of an 
iron blowing-pipe in the melted glass, and 
blowing through it with the mouth, accord- 
ing to the circumstances of the glass to be 
blow n. See G lass . 
Blowing of tin denotes the melting its 
ore, after being first burnt to destroy the 
mundic. 
BLUBBER, denotes the fat of whales 
and other large sea animals, of which is made 
train oil. 
The blubber is the adeps of the animal : 
it lies under the skin, and over the muscular 
flesh : it is about six inches in thickness, but 
about the under lip it is two or three feet 
thick. The quantity yielded by a good sized 
whale amounts to from forty to eighty hun- 
dredweight, or even more. ‘ The use of the 
blubber to the fish seems to be partly to 
poise the body, and partly to keep off the 
water at some distance from the blood; and 
thus it acts as clothing to keep the fish warm. 
BLUE, painter's, is made differently, ac- 
cording to the different kinds of painting. 
In limning, fresco, and miniature, they use 
indifferently ultramarine, blue ashes, and 
smalt: these are their natural blues, except- 
ing the last, which is partly natural, and 
partly artificial. 
In oil and miniature they also use indigo 
prepared, as also a factitious ultramarine. 
Enamellers and painters upon glass have 
also blues proper to themselves, each pre- 
paring them after their own manner. 
Blue, turnsole, is used in painting on 
wood, and is made of the seed of that plant : 
the way of preparing it is, to boil four ounces 
of turnsole in a pint and a half of water, in 
which lime has been slaked. 
Blue, Handers, is a colour bordering on 
green, and seldom used but in landscapes. 
Blueing nj meta's is performed bv heat- 
ing them in the lire till they assume a blue 
colour; particularly practised by gilders, 
who blue their metals before they apply the 
gold and silver leaf. 
Blue, to dye skins. Boil elder-berries of 
dwarf elder, then smear and wash the skins 
therewith, and wring them out; then boil 
the berries as before, in a solution of alum- 
water, and v et the skins in the same manner 
once or twice; dry them, and they will be 
very blue. 
_ A Blue for painting or staining of glass. 
1 ake fine white sand twelve ounces, zaffer 
and minium of each three ounces ; reduce 
them to a fine powder in a bell-metal mortar, 
then putting the powder into a very strong 
crucible, cover it and lute it well, and, be- 
ing dry, calcine it over a quick fire for an 
hour; take out the matter and pound it: 
Gg2 
then fo sixteen ounces of this nowder add 
fourteen of nitre powder; mix them well to- 
gether, and put them into the crucible again ; 
cover and lute it, and calcine for two hours 
on a very strong fire. 
Blue, Prussian. This blue is next to ul~ 
tramarine for beauty, if it is used in oil 1 
this colour does not grind well in water. 
Blue-bice is a colour of good brightness, 
next to Prussian blue, and also a colour of a 
body, and will flow pretty well in the pencil. 
Blue, Saunders, is also of very good use, 
and may serve as a shade to ultramarine, or 
the blue-bice, where the shades are not re- 
quired to be verj deep ; and is of itself a 
pleasant blue, to be laid between the light 
and shades of such a flower as is of a maza- 
rine blue. 
Blue, a fine one from Mr. Boyle. Take the 
blue leaves of rue, and beat them a little in 
a stone mortar with a wooden pestle ; then 
put them in water, juice and all, for fourteen 
days or more, washing them every day till 
they are rotten ; and at last beat them and 
the water together till they become a pulp, 
and let them dry in the sun. This is a fine 
blue for shading. 
Blue, Indigo. This makes the strongest 
shade for blues, and is of a soft warm colour, 
when it has been well ground, and washed 
with gum-water, by means of astone and a 
muller. 
Blue, Lacmus, or Litmus. This is a beau- 
tiful blue, and will run in a pen as free as 
ink. It is made of lacmus, and prepared 
thus : r I ake an ounce of lacmus, and boil :t 
in a pint of small beer wort, till the colour is 
as strong as you would have it; then pour 
off the liquor into a gallipot, and let it cool 
for use. T his affords a beautiful colour, has 
extraordinary effects, and is a holding co- 
lour ; if it is touched with aquafortis, it im- 
mediately changes to a fine crimson, little 
inferior to carmine. 
Blue, Japan. Take gum-water, what 
quantity you please, and white lead a suffi- 
cient quantify, grind them well on a poipby-* 
ry ; then take isinglass size, what quantity 
you please, of the finest and best smait a suf- 
ficient quantity, mix them well; to which 
add, of your white lead before ground, so 
much as may give it a sufficient body ; mix 
all these together to the consistence of a paint. 
Blueness of the skies. Sir Isaac Newton 
observes, that all the vapours, when they be- 
gin to condense and coalesce into natural 
particles, become first of such a bigness as 
to reflect the azure rays, before they can con- 
stitute clouds, or any other colour. 
But Mr. Melville supposes, that the clouds 
only reflect and transmit the sun’s light ; and 
that, according to their different altitudes 
they may assi me all the variety of colours at 
sun rising and setting, b) barely reflecting 
the sun’s incident light, as they receive it 
through a shorter or longer tract “of aii ; and 
the change is produced In the sun’s ravsby 
the quantity of air through which they 'pas-- 
from white to yellow, from yellow to orano-e’ 
and lastly to red. * & ’ 
BLUFF-HEAD, among sailors. A ship 
is said to be bluff-headed that has an upright 
stern. . b 
BOA, a genus of serpents belonging to the 
order of amphibia ; the generic character w 
scuta, or undivided plates, both on the abd^ 
men and beneath the tail. 
