BLE 
BLE 
The oxymurialic acid has also been used 
from its bleaching power in the manufacture 
of paper ; either the linen rags from which 
the paper is to be made being blanched by 
it, or, what has been regarded as preferable, 
the pulp into which they are reduced being 
submitted to its action. This method, 
though once extensively practised in this 
country, has been relinquished by many of 
our paper-manufacturers, as ithas been found, 
that in paper prepared with it, in the course 
of a few years the ink is altered, and its 
blackness even so much impaired, as to af- 
ford some reason for the suspicion that in 
time it will altogether fade; nor is this con- 
fined to writing ink, but has been observed 
even in printing ink. The effect is no doubt 
to be ascribed to a slight impregnation of 
the oxymuriatic acid; and this indeed can 
often be rendered perceptible by its odour, 
by breathing on paper which has been 
bleached in this manner. It might no doubt 
be removed by very careful washing of the 
pulp; but we have been informed by some 
intelligent paper manufacturers, that hie 
additional labour which would be requisite 
for this would upon the whole render the 
method more expensive than the old one. 
The process of bleaching by steam with 
an alkali at a high temperature, might pro- 
bably be advantageously employed. A 
branch of the manufacture, however, in 
which the acid necessarily must be used, 
is that of discharging the colours from co- 
loured rags, or to remove the ink from 
waste written paper. Even printed paper 
has been whitened by its agency, combined 
with that of an alkali, to remove the oily 
matter, and made to afford at least a coarser 
kind of paper. Ghaptal applied it to the 
purpose of restoring the colour of old books 
or prints, the paper being whitened by a 
very dilute acid, which did not act sensibly 
on the printing ink. 
Wax, reduced to thin plates, has been 
bleached by the oxymuriatic acid. The 
process succeeds best when the acid is used 
in the state of gas. Berthollet has an- 
nounced a peculiar effect obtained from the 
action of oxymuriatic acid, that of giving 
the appearance of cotton to hemp or flax. 
The process consists in immersing the flax, 
prepared by boiling, and by an alkaline so- 
lution in oxymi viatic acid of a certain 
strength, for some time, and alternating this 
immersion repeatedly with the action of an 
alkaiine ley. 
BLECHNUM, in botany, a genus of the 
Cryptogamia Filices, or Ferns. There are 
six species, all of them natives of warm or 
hot countries, excepting B.virginicum, which 
will bear the open air of England. They 
are increased by parting the roots. 
BENDE. See Zinc. 
BLENNIUS, blenny, in natural history, 
a genus of fishes of the order Jugulares. The 
generic characters are, head sloping ; body 
lengthened, sub-compressed, lubricous ; gill 
membrane six-rayed ; ventral fins two, 
three, or four-rayed, unarmed ; anal fin dis- 
tinct. There are two divisions ; viz. A. head 
crested ; B. head not crested ; and accord- 
ing to Gmeiin there are 18 species, though 
Dr. Shaw enumerates more. B. galerita, or 
crested blenny, inhabits the European 
ocean, is four or five inches long ; its body 
is brown and spotted ; the skin at the cor- 
ner of the upper jaw loose, projecting; dor- 
sal fin extending from the head almost to 
the tail ; ventral fin small ; vent under the 
ends of the pectoral fin. This fish is fre- 
quently found about the rocky coasts of 
Great Britain. B. ocellaris has above the 
eyes a single ray, and on the first dorsal fin 
a large black oceilate spot. It inhabits the 
Mediterranean Sea; is eight inches long; 
the body is without scales, dirty green, with 
olive streaks, rarely pale blue : the flesh is 
eatable, but in no great estimation. Al- 
though Linnaeus and others have described 
this fish as having two dorsal fins, Block 
considers it as having in reality but one, the 
sinking in of the middle part being in some 
specimens much deeper than in others, 
seems to be the cause of this difference cf 
opinion. B. saliens is a very small species, 
observed about the coasts of some of the 
southern islands, and particularly those of 
New Britain. It seems to be of a gregari- 
ous nature, and is seen swimming by hun- 
dreds, and flying as it were over the surface 
of the water, occasionally springing among 
the rocks. It is naturally formed for cele- 
rity in its movements, the pectoral fins be- 
ing very large in proportion to the body. 
They are nearly of a circular form when ex- 
panded, and when contracted reach almost 
as far as the vent on each side. B. superci- 
liosus has a small head, with large eyes, and 
silvery irides, and immediately over each 
eye is situated a small palmated crest, or 
appendage, divided into three segments. 
The body is covered with very small scales, 
and is of a yellow or gilded tinge, and mark- 
ed with numerous and irregular spots of 
dusky red. The dorsal fin commences at 
the back part of the head, and is continued 
almost to the tail ; but near its commence- 
