D i O 
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5'2f> 
root commonly weighs two or three pounds, 
though some yams have weighed upwards of 
twenty pound’s. With us it must be kept in 
the stove. 
DIOSCURI A, in Grecian antiquity, a fes- 
tival kept in honour of the Dioscuri, or Cas- 
tor and Pollux, wherein the assistants shared 
plentifully of tire gifts of Bacchus. 
DIOSMA, African spiriea, a genus of 
the monogynia order, in the pentaiidna class 
of plants ; and in the natural method rank- 
ing with those of which the order is doubtful. 
The corolla is pentapetalous, the nectarium 
crown-shaped above the germen : there are 
five capsules coalited ; the seeds hooded, 
liiefe are 19 species; of which the most re- 
markable are the hirsuta, with narrow hairy 
leaves; and the . oppositifolia, with leaves 
placed in the form of a cross. The first is a 
very handsome shrub, growing to the height 
of five or six feet : the stalks are of a line 
coral colour: the leaves come out alternate- 
ly on every side of the branches, and are 
narrow-pointed and hairy: the flowers are 
produced in small clusters at the end of the 
shoots, and are of a white colour. They are 
succeeded by starry seed-vessels having live 
corners; in each o? which corners is a cell, 
containing s one smooth, shining, oblong, black 
seed: these seed-vessels abound with a resin 
which emits a grateful scent, as does also the 
whole plant. The second species rises to 
the height of three or four feet: the branches 
are slender, and produced from the stem 
very irregularly ; the leaves are placed cross- 
wise ; the flowers are produced at the ends 
of the branches, between the leaves: the 
plants continue a long time in flower, and 
make a line appearance when they are inter- 
mixed with other exotics in the’ open air. 
Both species are propagated by cuttings; 
which may be planted during any of the sum- 
mer months in pots, and plunged into a mo- 
derate hotbed, where they should be shad- 
ed from the sun, and frequently watered. In 
* about two months they will have taken root ; 
when each should be transplanted into a 
small pol where they are to remain ; but 
during winter, like most other exotic plants, 
they must be preserved in a greenhouse. 
DIOSPYROS, the Indian date-plum; 
a genus of the dioecia order, in the polygamia 
class of plants ; and in the natural method 
ranking under the 18th order, bieornes. The 
calyx is hermaphrodite and quadrifid ; the 
corolla urceolated and quadrifid ; there are 
eight stamina ; the style quadrifid ; the berry 
octospermous : the male calyx, corolla, and 
stamina, as in the former. There are 9 spe- 
cies ; the most remarkable are : 1 . The lo- 
tus, which is supposed to be a native of Af- 
rica, whenee it was transplanted into several 
parts of Italy, and also into the south of 
France. The fruit of this tree is supposed to 
be the lotus with which Ulysses and his com- 
panions were enchanted, ’and which made 
those who ate of it forget their country and 
relations. In the warm parts of Europe, 
this tree grows to the height of 30 feet. In 
the botanic garden at Padua, there is one 
very old tree which lias been described by 
some of the former botanists under the title 
of guajacnm patavinum. This tree produces 
plenty of fruit every year ; from the seeds 
of which many plants have been raised. 2. 
The Yirginiana, pinshamin, persimon, or 
pitchumon plum, is a native of America, but 
particularly of Virginia and Carolina. The 
seeds ot this sort have been frequently im- 
ported into Britain, and the trees are com- 
mon in many nurseries about London. It 
rises to the height of 12 or 14 feet ; but ge- 
nerally divides into many irregub.r trunks 
near the ground, so that it is very rare to 
see a handsome tree of this sort. Though 
plenty of fruit is produced on these trees, "it 
never comes to perfection in this country. 
In America the inhabitants preserve the fruit 
till it is rotten, as is practised with medlars 
in England ; when it is esteemed very 
pleasant. Both species are propagated by 
seeds • and the plants require to be treated 
tenderly while young ; but when they are 
grown up, they’ resist the greatest cold of 
this country. See Plate Nat. Hist. fig. 171. 
DIPHTHONG, in grammar, a double 
vowel, or the mixture of 2 vowels pronoun- 
ced together, so as to make one syllable. 
DIPHYSA, a genus of the class and order 
diadelphia decandria. The cal. is half live- 
cleft ; legume with a bladder on each side; 
seeds hooked. There is one species, a small 
tree of New Spain. 
DIPS AC US, teazel, a genus of the mo- 
nogynia order, in the telrundria class of 
plants ; and in the natural method ranking 
under the 48th order, aggregate. The com- 
mon calyx is polyphyllous, proper above ; 
the receptacle paleaceous. There are four 
species ; the most remarkable of which is 
the dipsacus fullouum, which grows wild in 
many parts of England. It is of singular 
use in raising the nap upon woollen cloth. 
I' or this purpose, the heads are lixed round 
the circumference of a large broad wheel, 
which is made to turn round and the cloth is 
held against them. In the west of England, 
great quantities of this plant are cultivated 
for the use just-mentioned. It is propagated 
by sowing the seeds in March, upon a soil 
that is well prepared. About one peck of 
seed is sufficient for an acre, as the plants 
must have room to grow ; otherwise the 
heads will not be large enough, nor in great 
quantity. When the plants come up, they 
must be hoed in the same manner as is prac- 
tised for turnips, cutting down all the weeds, 
and thinning the plants to about eight inches 
distance : and as the plants advance, and 
the weeds begin to grow again, they must 
be hoed a second time, cutting out the plants 
to a wider distance, so that they may finally 
stand a foot distant from each* other. The 
second year they will shoot up heads, which 
may be cut about the beginning of August. 
They are then to be tied up in bunches, "and 
set in the sun if the weather is fair ; if not, 
in rooms to dry them. The common pro- 
duce is about 1 Go bundles or sheaves upon an 
acre, which are sold for one shilling each 
DIPTERYX, a genus of the diadelphia 
decandria class and order. The cal. has the 
two upper segments winged ; legume ovate, 
compressed, one-seeded. There are two 
species, tall trees of Guiana. 
DIPLOMA, an instrument of licence 
given bv colleges, societies, &c. to a clergy- 
man to exercise the ministerial function, or 
to a physician to practise the profession, &c. 
after passing examination or admitting him 
to a degree. 
DIPPING, among miners, signifies the 
interruption, or breaking off, of the veins of 
ore ; an accident that gives them a great 
D I P 
deal of trouble before they can discover the 
ore again. 
DIPPING needle. See Magnetism, 
and Navigation. 
DIPTERE, or Dipteron, in the antient 
architecture, signified a temple surrounded 
with two rows of columns, which formed a sort 
of porticoes, called wings or isles. Pseudo- 
diptere is the same, except that instead of 
the double row of columns, this was only 
encompassed with a row of single ones. 
DIPTYCHS, in antiquity, a public re- 
gister, in which were written the names of 
the consuls and other magistrates among the 
heathens ; and among the Christians, they 
were a sort of tablets, on one of which were 
written the names of the deceased, and on 
the other those of the bring patriarchs, 
bishops, &c. or those who had done anv ser- 
vice to the churcjj, for whom prayers were 
offered, the deacon reading the names at 
mass. 
DIPUS, jerboa, a genus of quadrupeds 
of the glires order. The generic character 
is, front-teeth two above and below : fore- 
legs very short ; hind-legs very long : cla- 
vicles in the skeleton. 
1. Dipus sagitta, or common jerboa. This 
is the species which seems to have been 
known to the ancients under the name of 
//.Ur Snrw, or two-footed mouse, and which is 
represented, though with no great degree of 
exactness, on some coins of Gyrene, where 
it was antiently found in great abundance, 
and where it still continues, it is supposed 
to be the saphan of the scriptures, it is about 
the size of a rat, and is of a very pale tawny- 
brown above, and white beneath ; and across 
the upper part of the rump runs an obscure 
dusky band, which is probably not a perma- 
nent character, since it appears to be more 
or less distinct in different individuals. The 
head is short ; the ears thin, broad, upright, 
and rounded: the eyes large, round, and 
dark-coloured : the fore legs about an inch 
long, with five toes to each foot: the hind 
legs are extremely long, thin, sparingly co- 
vered with short hair, and very much re- 
semble those of a bird : the hind feet have 
three toes each, the middle of which is 
somewhat longer than the rest, and all are 
furnished with sharp and strong claws : there 
is also a very small spur or back toe, with its 
corresponding claw. 
The usual le ngth of the common jerboa, 
from nose to tail, is about seven inches and 
a quarter: the tail is about ten inches long, 
of a form rather inclining to square than cy- 
lindric, and of the same colour with the 
body, but terminated by an elegant, ilattish, 
oval tuft of black hair, with a white lip. On 
each side the nose are situated several very 
long hairs or whiskers, as is usual in most 
animals ot this tribe: the cutting-teeth are 
sharp and strong, and resemble those of a 
rat. In its attitudes and manner of progres- 
sion this animal resembles a bird ; generally 
standing, like the kangaroo, on its hind feet, 
and leaping with much celerity, and to a 
great distance : but sometimes it sets its 
fore feet to the ground for a moment or two, 
and then recovers its former attitude. It 
principally uses the fore legs in feeding; pull- 
ing to its mouth the ears of corn, and vari- 
ous other vegetable substances on which it 
feeds. It inhabits subterraneous holes, which 
it either prepares itself, or finds ready exea- 
