B L A 
B L E 
22 * 
order, alg^. The male calyx is cylindric, 
replete with grains ; tiie female calyx is 
naked; the fruit roundish, immersed in the 
leaves, and many-seeded. Of this genus there 
is but one Species known, viz. 
Blasia pusilla, which grows naturally on the 
banks of ditches and rivulets, in a gravelly or 
sandy soil, in England. It grows Hat upon 
the ground in a patch, composed of numerous 
thin, green, pellucid leaves, marked with a 
few whitish veins near the base, divided and 
subdivided into obtuse segments obscurely 
crenated on the edges. The margins of the 
leaves are a little elevated, but the interior 
parts adhere close to the ground by a fine 
down which answers the purpose of roots. 
The seeds are so small as to be almost imper- 
ceptible. 
BLASPHEMY: all blasphemies against 
God; all contumelious reproaches of Jesus 
Christ; all profane scoffing at the holy scrip- 
tures, or exposing any part of them to ridi- 
cule ; are punishable by fine, imprisonment, 
and such corporal punishment as to the 
court shall seem meet, according to the hein- 
ousness of the crime. 1 Hew. (j. 
BLAST, a disease in grain, trees, &c. 
The sugar-cane in the West Indies is subject 
to a disease of this kind, which is thought to 
be occasioned by the aphis of Linmeus, 
which is distinguished into the black and yel- 
low ; of these, the latter is most destructive. 
It consists of myriads of insects, invisible to the 
naked eye, whose proper food is the juice of 
the cane, in search of which they wound the 
tender blades, and in the end destroy the 
vessels. It is said the blast never attacks 
those plantations where colonies have been 
introduced of the carnivorous ant, or formica 
onmivora. These minute and busy crea- 
tures soon clear a sugar-plantation of rats ; 
their natural food consists of all kinds of in- 
sects and animalcula. 
Blast, a term used at iron-foundries to de- 
note the column of air introduced into the 
furnace for the purpose of combustion. 
BLASTING, a term used by miners for 
the tearing up rocks which lie in their way, 
by the force of gunpowder. 
In order to do this a long hole is made in 
the rock, which being charged with gunpow- 
der, they fill it up; leaving only a touch-hole, 
with a train or match to tire the charge. 
BLA 1 1 A, a genus of hymenopterous 
insects, called in England cock roaches, or 
vulgarly and erroneously, black beetles. 
The head is inflected ; antennae setaceous ; 
feelers unequal and filiform ; wings and wing- 
cases smooth, the latter somewhat coriaceous; 
thorax flattish, orbicular, and margined; legs 
formed for running ; abdomen terminating in 
two articulated appendages above the tail. In 
hotter climates the blatta are a very trouble- 
some race : -they enter houses and commit va- 
rious depredations on the furniture, devour 
provisions of every kind, destroy dot lies, and 
torment the inhabitants with their bite. The 
blatta most abundant in England was origi- 
nally irom the east, or as some imagine from 
America: it is now completely naturalized to 
our climate ; and the best method of clearing 
houses of (hem, is to employ the agency of a 
tame hedgehog, who very soon devours 
them all. 
AH the known species of this insect, 
whether in the larva, pupa, or perfect winged 
state, secrete themselves in the day-time, and 
V'OL. I. 
BLE 
j wander about in the night in search of food ; 
hence they were called by the ancients luci- 
fugie, insects that shun the light. The fol- 
lowing species are enumerated by Linnseus 
and others, viz. gigantea, madera, aegyptica, 
occidental is, surinamensis, americana" (See 
Plate, Nat. Hist. fig. 46,) australasiae, ery- 
thocephala, capensis, indica, nivea, irrorata, 
viridis, brasiliensis, peliveriana, oriental is, 
cincta, picta, variegata, lapponica, germanica, 
ruficollis, maculate, marginata, oblongata, 
nitidula, fusca, deusta, chlorotica, latissima, 
aterrima, perspecillaris, asiatica, schceferi, 
sylvestris, pennsylvanica, livida, rufa, grisea, 
minutissima, aptera, punctulata, ocellata. 
BLAZONING, or Blazonry, in herald- 
ry, the art of decyphering the arms of noble 
families. The word originally signified the 
blowing or winding of a horn, and was intro- 
duced into heraldry as a term denoting the 
description of things borne in arms, with 
their propier significations and intendments, 
from an antient custom the heralds, who 
were judges, had of winding an horn at justs 
and tournaments, when they explained and 
recorded the achievements of knights. In 
blazoning a coat of arms, you must always 
begin with the field, and next proceed to the 
charge; and if there are many things borne 
in the field, you must first name that 
which is immediately lying upon the field. 
A our expressions must be very short and 
expressive, without any expletives, needless 
repetitions, or particle's. Such terms for the 
colours must be used, as are agreeable to the 
station and quality of the bearer. All persons 
beneath the degree of a noble, must have 
their colours blazoned by colours and metals ; 
noblemen by precious stones, and kings and 
princes by planets. 
BLEA, in the anatomy of plants, the 
inner rind or bark. See Physiology of 
Plants. 
BLEACHING. The art of bleaching is 
of great antiquity. The ancients were ac- 
quainted with the detersive quality of some 
kinds of clay, and the effect produced by the 
action of the atmosphere, moisture, afid light, 
on the stuffs exposed to them. Health and 
cleanliness rendered it necessary to devise 
quicker methods than these ; and the pro- 
perty of soaps and leys of ashes was there- 
fore soon discovered. 
In the present age, the arts, following sci- 
ence with dose steps, have taken advantage 
of processes and detersive menstrua, the ex- 
istence of which was before unknown ; these 
discoveries have succeeded each other with 
such rapidity, that the last eight or ten years 
have effected a complete revolution in the 
art of bleaching. 
This art is naturally divided jnto two dis- 
tinct branches ; the bleaching of vegetable, 
and of animal substances. These being of 
very different natures, require different pro- 
cesses for whitening them. Vegetables con- 
sist of oxygen, hydrogen, and carbon, of 
which the latter is in the greatest proportion ; 
while animal substances, besides these, con- 
tain also a large quantity of azote, and also 
phosphorus and sulphur. 
Bleaching afflux and hemp. If ripe flax 
is examined, it will be found to be composed 
of fibres or filaments united together by the 
sap, enveloping a semiligneous substance, 
and covered with a thin bark. It is the 
fibrous part only that is used for making cloth. 
and it must therefore he previously separated 
from t he other matters. 
The sap or succulent part is composed of 
extractive principle and water, and the first 
process is to separate this substance, which 
holds the filaments together. As soon as 
the llax is pulled, it is steeped in soft water 
until the putrefactive fermentation takes 
place. This degree of fermentation begins 
with the succulent part, as being more suscep- 
tible of decomposition than the rest. Was 
the llax to be continued long in this state, 
the whole substance of it would be decom- 
posed or destroyed, upon the same principle 
that malt is injured by too long steeping, or 
that wort loses its substance by too long a 
fermentation. It must therefore be taken 
out of the water while yet green, and before 
the whole of its sap is separated. Well 
water and brackish water must be carefully 
avoided, as well as that which flows over gyp- 
seous soil. Such water accelerates putre- 
faction, and hurts the quality of the hemp and 
flax. This is perfectly agreeable to the prin- 
ciples of chemistry ; it is thus that a little 
salt accelerates animal putrefaction, while a 
great quantity tends to prevent it. The 
portion of saline substances taken up by the 
water, hastens corruption, by extending the 
putrid fermentation even to the filaments, 
which it blackens and spoils, while' it ought 
to operate only on thejuices. 
The flax, when taken from the water, is 
spread out upon the grass to dry. During 
the fermentation and decomposition which 
thence result, there is a speedy combination 
°f oxygen and carbon. Exposure on the 
grass facilitates the escape of the carbonic 
acid into the atmosphere, and the plants 
become of a whitish grey colour. 
It is known that a ley very slightly alkaline 
may be substituted with advantage, for this 
long and noxious operation ; it is therefore 
certain, that a chamber from 20 lo 30 feet in 
length, into which the steam of alkaline 
caustic water, of the strength of one-fourth 
of a degree only, is introduced, will be suf- 
ficient to produce the same effect as watering 
on an immense quantity of hemp and flax", 
suspended on basket-work, in less time, and 
w ith less expence, than are required for the 
different manipulations of watering. The 
losses occasioned by the negligence of work- 
men, who, by suffering the hemp and flax 
to macerate too long, give time to the de- 
composition to reach the filaments, which 
renders them brittle, and occasions a con- 
siderable waste, will also be avoided. In on r 
process, the artist can follow' every moment 
the progress of his operation, and stop it at 
the favourable period. 
Nothing now r remains but the wood, and 
(he flax or fibrous part. The wood is a hol- 
low tube covered over very compactly with 
the flax. To separate the wood, it must bo 
kiln-dried, in order to render it frangible or 
brittle ; but care must be taken not to apply 
too much heat, for fear of injuring the flay. 
It is next to be beaten or broken, by which 
means the flax is not only divided into small 
fibres, but most of the wood is separated, 
and the part which adheres is reduced to 
small fragments. To separate these again, 
the flax is to be scutched, or thrashed, ig 
small parcels at a time, either by manual 
labour, or mills contrived for the purpose. 
Hackling is the last process; which is nothing 
