IGN 
the dead when God shall think fit. These 
doctrines, commonly received by the Jews 
to this day, were drawn up about the 
end of the eleventh century, by the famous 
Jewish rabbi, Maimonides. 
Here in England, in former times, 
the Jew's and all their goods belonged 
to the chief lord where they lived ; and 
he had such an absolute property in them, 
that he might sell them ; for they had not 
liberty to remove to another lord without 
leave. They were distinguished from the 
Christians in their lives, and at their dealhs ; 
for they had proper judges and courts, 
where their causes were decided. By stat. 
Edward I. the Jews, to the number of 
15,000, were banished out of England; and 
never returned, till Oliver Cromwell re-ad- 
mitted them. Whenever any Jew shall 
present himself to take the oath of abjura- 
tion, in pursuance of the 10 George III. 
c. 10, the words — upon the true faith of a 
Christian — shall be omitted out of the oath 
in administering it to such persons ; and the 
taking the oath, by persons professing the 
Jewish religion, without these words, in 
like manner as Jews are admitted to give 
evidence in the courts of justice, shall be 
deemed a sufficient taking of the abjura- 
tion-oath, If Jewish parents refuse to al- 
low their Protestant children a mainte- 
nance suitable to their fortune, the Lord 
Chancellor, upon complaint, may make 
such order therein as he may think proper. 
Jews' harp, in music, an instrument well 
known among the lower classes in this coun- 
try, but almost the only musical instrument 
made use of by the inhabitants of the island 
of St. Kilda. 
IGN AT I A, in botany, a genus of the 
Pentandria Monogynia class and order. 
Natural order of Lurid®. Apocine®, Jus- 
sieu. Essential character : calyx five-tooth- 
ed ; corolla funnel-form, very long ; fruit 
one-celled, many-seeded. There are two 
species, viz. I. amara, and I. longiflora. 
IGNITION, in chemistry, is that illumi- 
nation, or emission of light, produced in bo- 
dies by exposing them to a high tempera- 
ture, and which is not accompanied by any 
other chemical change in them. It may be 
distinguished from combustion, a process in 
which there is also the emission of light and 
heat. Combustion is the result, not of mere 
increase of temperature in the body which 
suffers it, but of the chemical action of the 
air, or of a principle which the air contains : 
hence combustible substances are alone sus- 
ceptible of it, and when the process has 
ILE 
% 
ceased, the body is no longer combustible. 
Ignition is an effect of the operation of ca- 
loric alone; it is wholly independent of the 
air ; all bodies, at least solid and liquid sub- 
stances, are equally susceptible of it, and 
if it has ceased, from a reduction of tempe- 
rature, it may be renewed by the tempera- 
ture being again raised. The point of tem- 
perature at which the first stage of ignition 
takes place, or at which bodies arrive at a 
red heat, appears to be the same in all, and 
is supposed to be about 800° of Fahrenheit. 
By raising the temperature, the illumina- 
tion becomes brighter, and the red light 
acquires a mixture of yellow rays. At 
length, by still increasing it, we come to the 
white heat, which is the highest state of ig- 
nition. Aeriform fluids are not brought in- 
to a state of illumination by heat. The 
phenomena are produced, not only by the 
application of heat, but likewise by friction 
and attrition. 
JIB, in naval affairs, the foremost sail of 
a ship being a large stay-sail extended from 
the outer end of the bowsprit, prolonged by 
the jib-boom, towards the fore-top-mastt 
head. In cutters and sloops, the jib is on 
the bow-sprit, and extends towards (he 
lower masthead. The jib is a sail of great 
command with any side wind, but espe- 
cially when the ship is close-hauled, or lias 
the wind upon her beam ; and its effort in 
turning her head to leeward is very power- 
ful, and of great utility, particularly when 
the ship is working through a narrow chan- 
nel. Jib-boom is a continuation of the 
bow-sprit forward, being run out from the 
extremity in a similar manner to a top-mast 
on a lower mast, and serving to extend the 
bottom of the jibs and the stay of the fore- 
top-gallant-mast. 
JIGGER, in naval affairs, a machine con- 
sisting of a piece of rope five feet long, with 
a block at one end, and a sheave at the 
other, used to hold on the cable when it is 
heaved into the ship by the revolution of the 
windlass. This is particularly useful, when 
either slippery with mud or ooze, or when 
it is stiff and unweildy, in both which cases 
it is very difficult to stretch it back from 
the windlass by hand, which however is 
done with facility and expedition by means 
of the jigger. 
ILEX, in botany, holly, a genus of the 
Tetrandria Tetragynia class and order. Na- 
tural order of Bumos®. Rhamni, Jussieu. 
Essential character : calyx four-toothed ; 
corolla wheel-shaped ; style none ; berry 
four-seeded. There are sixteen species. 
