PLA 
PLA 
ased either as stakes, or the other work ef 
the plashing ; the ditch is to be cleaned out 
with the spade : and it must be now dug 
as at first, with sloping sides each way ; 
and when there is any cavity on the bank 
on which the hedge grows, or the earth has 
been washed away from the roots of the 
shrubs, it is to be made good by facing it, 
as they express it, with the mould dug from 
the upper part of the ditch : all the rest of 
the earth dug out of the ditch is to be laid 
upon the top of the bank. 
In plashing the quick, two extremes 
are to be avoided ; these are, the laying it 
too lowq and. the laying it too thick-: this 
makes the sap run all into the shoots, and 
leaves the plashes without sufficient nou- 
rishment ; which, with the thickness of the 
hedge, finally kills them. The other ex- 
treme of laying them too high, is equally to 
be avoided ; for this cafries up all the nou- 
rishment into the plashes, and so makes the 
shoots small and weak at the bottom, and, 
consequently the hedge tliin. 
PLASMA, in mineralogy. The colour 
of this mineral is intermediate between 
grass and leek green, and of ditt'erent dc- 
gi'ees of intensity. It is marked with ochre 
yellow dots, and whitish spots. It occurs 
in angular pieces; internally it is glistening ; 
fracture perfectly flat conchoidal. It is 
hard, brittle, easily frangible; not very 
heavy. It has been found in Italy, Ger- 
many, and Turkey, but chiefly among the 
ruins of Rome. It is said tliat it was for- 
merly worn by the Romans as a part of 
ornamental dress. 
PLASTER, in pharmacy, is defined to 
be an external application, of a harder con- 
sistence than oiir ointments : these are to 
be spread according to the different circum- 
stances of the wound, place, or patient, 
either upon linen or leather. See Phar- 
macy. 
Piaster, among builders, &c. The 
plaster of Paris is a preparation of several 
species of gypsums, dug near Mont Mai- 
tre, a village in tlie neighbourhood of Pa- 
ris ; whence the name. See Mortar. 
PLATANUS, in botany, plane tree, a 
genus of the Monoecia Polyandria class 
and order. Natural order of Amentaceae. 
Essential character : male, calyx ament glo- 
bular ; corolla scarcely apparent ; anthers 
growing round the filament : female, calyx 
ament globular ; corolla many-petalled ; 
stigma recurved ; seeds roundish, mucro- 
nate with the style, pappose at the base. 
There are two species, viz, P. orientaUs, 
oriental plane tree, and P. occidental!*^ 
American plane tree ; these are very large, 
handsome, and lofty trees. The first’ sort, 
or eastern plane tree, grows naturally in 
Asia ; the stem is tall, erect, and covered 
with a smooth bark, which annually falls 
ofi'; it sends out many side branches, and 
are generally a little crooked at their joints ; 
the leaves are placed alternate, on foot- 
stalks an inch and a half long ; tlie flowers 
come out upon long peduncles, hanging 
downward, each sustaining five or six round 
balls of flowers ; the upper, which are tlie 
largest, are more than four inches in circum- 
ference ; these sit very close to tlie pedun- 
cle ; the bristly down surrounding the seeds 
helps to transport tliem to a great distance. 
PLATALEA, the spoonbill, in natural 
history, a genus of birds of the order Gral- 
1®. Generic character: bill long, broad, 
flat, and thin, the end widening into a 
roundish form ; nostrils small at the base of 
the bill; tongue short and pointed; feet 
four-toed and semi-palmated. There are 
three species. ‘ 
P. leucerodia, or the white spoonbill, in- 
habits Europe, Asia, and Africa, and sub- 
sists on frogs and fislies, snakes and grass.^ 
It is of the size of a heron ; it frequents 
the sea coasts, near which it builds in the 
highest trees, and, in the breeding season, 
is nearly as clamorous as the rook. These 
birds are migratory, and withdraw to warm 
regions on the approach of winter. Their 
flesh has a strong resemblance in taste to 
that of a goose. See Aves, Plate XII. 
fig. 4. 
The Brazilian spoonbill is somewhat less 
than the above, and its plumage is nearly 
throughout of an exquisite rose colour. 
The scarlet spoonbill, a variety of the 
last, is of the colour from which it is named, 
w'hich, however, it does not attain till its 
third year. It is of the same size as the 
last, and found in Jamaica and Mexico. 
The dwarf spoonbill is of the size of a 
sparrow, and inhabits South America. 
PLATE, in heraldiy, is a round flat 
piece of silver, without any impression; 
but as it were formed, ready to receive it. 
Plate is also a term used by our sports- 
men, to express the reward given to the 
best horse at our races. 
Plates, in gnnnery. The prise-plates 
are two plates of iron on the cheeks of a 
gun-carriage, from the cape square to the 
centre, through which the prise-bolts go, 
and on which the handspike rests when it 
pobes up the breech of the piece. Breast- 
