J E W- 
I L E 
5 
J'E L 
whose vertices meet in the centre of n 
sphere, supposed to circumscribe it, and 
therefore have their height and bases equal; 
wherefore the solidity of one of those pyra- 
mids multiplied by 20, the number of bases, 
gives the solid content of the icosahedron. 
If fig- 127, Plate Miscel. be nicely drawn 
on pasteboard, cut half through, and then 
folded up neatly together, it will represent 
an icosahedron. Seelig. 128. 
To form an icosahedron, describe upon 
card paoer 20 equilateral triangles; cut it out 
by the extreme edges, and cut all the other 
lines halt-through ; then fold up by these 
edges, and the solid will be formed. The 
linear edge of the icosahedron being A, then 
the surface wall be 5 A 2 \/ 3 — 8.6GO A 2 , and 
the solidity .5 A' ^ f -- 
“ | — 3 \/ 5 
= 2.1817 A\ 
ICOSANDRIA, from eixo<x< “twenty,” and 
arnp, “ a man or husband;” the name of the 
J2tn class in Linnaeus’s sexual method, con- 
siting of plants with hermaphrodite flowers, 
which are furnished with 20 or more stamina, 
that are inserted into the inner side of the 
calyx or petals. See Botany. 
IDES, idus, in the antient Roman calen- 
dar, were eight days in each month, the lirst 
of which fell on the 15th of March, May, 
July, and October, and on the 13th day of 
other months. They were reckoned back- 
wards: thus they called the 14th day of 
March, May, July, and October, and the 
12th of the other months, the pri-die idus, 
or the day before the ides ; the next preced- 
ing day, they called the tertio idus; and so 
on, reckoning always backwards, till they 
came to the nones. This method of reckon- 
ing time is still retained in the chancery of 
Rome, and in the calendar of the breviary. 
IDIOT ', is a fool or madman from his na- 
tivity. By the old common law there is a 
writ de idiota inquirendo, directed to the 
sheriff, to inquire by a jury whether the party 
is an idiot or not; and if they find him a per- 
fect idiot, the -profits of his lands and the 
custody of his person belong to the king, ac- 
cording to the stat. 17 Ed. IT c. y. by which 
it is enacted, that the king shall have the cus- 
tody of the lands of natural fools, taking the 
profits of them without waste or destruction, 
and shall find them necessaries, of whose fee 
soever the land shall be holden. And after 
the death of such idiots, he shall render it to 
the right heir, so that such idiots shall not 
alien, nor their heirs be disinherited. But 
it seldom happens that a jury finds a man an 
idiot from his nativity, but only non co epos 
mentis from some particular time, which has 
an operation very different in point of law ; 
for in this case he comes under the denomi- 
nation of a lunatic, in which respect the king 
Shall not have the profits of his lands, but is 
accountable for the same to the lunatic when 
he comes to his right mind, or otherwise to 
his executors or administrators. 1 Black. 303. 
JEER, or Jeer-rope, in a ship, is a large 
rope reeved through double or treble blocks, 
lashed at the mast-head, and on the yard, in 
order to hoist or lower the yards. 
JEJUNUM. See Anatomy. 
JELL Y, in chemistry. If we press out the 
juice of ripe blackberries, currants, and many 
other fruits, and allow it to remain for some 
time in a state of rest, it partly coagulates into 
a tremulous soft substance, well known by the 
name of jelly. If we pour off the uncoagu- 
lated parts, and wash the coagulum with a 
small quantity of wate’r, we obtain jelly ap- 
proaching to a state of purity. 
In this state it is nearly colourless, unless 
tinged by the peculiar colouring matter of 
the fruit; it has a pleasant taste, and a tre- 
mulous consistency. It is scarcely soluble in 
cold water, but very soluble in hot water; 
and when the solution cools, it again coagu- 
lates into the form of a jelly. When long 
boiled, it loses the property of gelatinizing 
by cooling, and becomes analogous to muci- 
lage. This is the reason that in making cur- 
rant-jelly, or any other jelly, when, the quan- 
tity of sugar added is not sufficient to absorb 
all the watery parts of the fruit, and conse- 
quently it is necessary to concentrate the 
liquid by long boiling, the mixture often loses 
the property of coagulating, and the jelly, ot 
course, is spoiled. 
Jelly combines readily with alkalies. Nitric 
acid converts it into oxalic acid, without se- 
parating any azotic gas. When dried it be- 
comes transparent. When distilled it affords 
a great deal of pyromucous acid, a small 
quantity of oil, and scarcely any ammonia. 
Jelly exists in all acid fruits, as oranges, 
lemons, gooseberries, See. If the juice of 
these fruits is allowed to gelatinize, and then 
poured upon a searce, the acid gradually fil- 
tres through, and leaves the other; which 
may be washed with a little cold water, and 
allowed to dry. Its bulk gradually diminishes, 
and it concretes into a hard transparent brittle 
mass, which possesses most of the properties 
of gum. Perhaps, then, jelly is merely gum 
combined with vegetable acid. 
Jelly , animal. See Gelatine. 
JESUIT'S, or the society of Jesus, a most 
famous religious order in the Romish church, 
founded by Ignatius Loyola, a native of Gui- 
puscoa in Spain, who in the year 1738 assem- 
bled ten of his companions at Rome, princi- 
pally chosen out of the university of Paris, 
and made a proposal to them to form a new 
order; when, after many deliberations, it was 
agreed to add to the three ordinary vows of 
chastity, poverty, and obedience, a fourth, 
which was, to go into all countries whither 
the pope should please to send them, in order 
to make converts to the Romish church. 
Two years after, pope Paul III. gave them a 
bull, by which he approved this new order, 
giving them a power to make such statutes 
as they should judge convenient; on which, 
Ignatius was created general of the order, 
which in a short time spread over all the 
countries of the world, to which Ignatius sent 
his companions, while he staid at Rome, 
whence he governed the whole society. The 
order was abolished by pope Clement XIV. 
(Ganganelli) in 1773. See Gregory’s Church 
History, vol. ii. 
JEsuiT’s-/;«r£. SeeCiNCHONA, and Phar- 
macy. 
JET. See Coal. 
Jet d’eau. See Hydraulics. 
JET SON, Jetsen, or Jetsam, inlaw, is 
used for any thing thrown out of a ship or 
vessel that is in danger of being a wreck, and 
which is driven by the waves on shore. 
JEWS. In England in former times, the 
Jews and all their goods belonged to the chief 
lord where they lived. By stat. Ed. I. the 
Jews, to the number of 15,000, wrere banish- 
ed out of England, and never returned till 
Oliver Cromwell readmitted them. 
Whenever any Jew shall present himself to 
takethe oath of abjuration, in pursuance of the 
10 Geo. 111. c. 10. the words, upon the true 
faith of a Christian, shall be omitted out of 
the said oath in administering it to such poi- 
sons; and the taking the said oath by persons 
professing the Jewish religion, without thy 
said words, in like manner as Jews are ad- 
mitted to give evidence in courts of justice, 
shall be deemed a sufficient taking of it. 
JGNATTA, a genus of the monogynia 
order, in the pentanclria class of plants. T he 
calyx is five-tootbed; the corolla is long ; the 
fruit an unilocular plum, with many seeds. 
T here are two species, the principal of which 
is the amara, a native of India. The fruit of 
this tree contains the seeds called St. Igna- 
tius’s bt-ans. According to some, it is from 
this plant that the Colombo root is obtained. 
IGNIS Eatuus, a common meteor, chiefly 
seen in dark nights about meadows, marshes, 
and other moist place-, as also in burying- 
grounds, and near dung-hills. It is known 
among the people by the appellations, \V ill 
with a wisp, and Jack with a lantern. See 
Meteors. 
IGNITION. See Caloric, and Che- 
mistry. 
IGNORAMUS, was formerly indorsed by 
the grand jury on the back of a bill, for which 
they did not find sufficient evidence ; but 
now, since the proceedings were in English, 
they indorse “ no bill,” or “ not a true bill,” 
or which is the better way, “ not found.” 4 
305. 
IGUANA. See Lacerta. 
JIB, the foremost sail of a ship, being a - 
large stay-stail extended from the outer end 
of the bowsprit prolonged by the jib-boom, 
towards the fore-top-mast-head. See Sail. 
hn-booi/i, a boom run out from tiie extre- 
mity of the bowsprit, parallel to its length, 
and’ serving to extend the bottom of the jib, 
and the stay ot the fore-top-gallant-mast. 
ILEX, the holm or hath/ tree, a genus of 
the tetragynia order, in the tetrandria class 
of plants, and in the natural method ranking 
under the 43u order, dumosse. T he calyx is 
quadridentated ; the corolla rotaceous ; there 
is no style; the berry is monospermous. 
T here are 16 species of this genus ; but the 
most remarkable is the aquifolium, or com- 
mon holly. Of this there are a great mini- - 
her of varieties with variegated leaves, 
which are propagated by the nursery gar- 
deners for sale. The best of these varieties 
are the painted-lady holjy, British holly, 
Bradley’s best holly, phyllis or cream holly, 
milkmaid holly, Pritchet’s best holly, gold- 
edged hedgehog holly, Chyney’s holly, glory- 
of-the-west holiy, Broaderick’s holly, Par- 
tridge’s holly, ' Herefordshire white boll}-. 
Blind’s cream holly, Longstaff s holly, Eales’s 
holly, silver-edged hedgehog holly. All these 
varieties are propagated by budding or graft- 
ing them upon stocks of the common green 
holly. 
Sheep in the winter are fed with croppings 
of holly. Birds eat the berries. T he bark 
fermented, and afterwards washed from the 
woody fibres, makes the common birdlime. 
The plant makes an impenetrable fence, and 
bears dropping ; however, it is not found in. 
