JAC 



JAL 



I. 



I or i, the ninth letter, and third vowel 

 5 of the alphabet, is pronounced by 

 throwing- the breath suddently against the 

 palate, as it comes out of the larynx, with 

 a small hollowing of the tongue, and 

 nearly the same opening of the lips as in 

 pronouncing a or e. Its sound varies ; in 

 some words it is long, as high, mind, &c.: 

 in others short, as bid, hid, sin, &c. ; in 

 others again it is pronounced like y, as in 

 collier, onion, &c. : and in a few it sounds 

 like ee, as in maclrine, magazine, &c. No 

 English word ends in i, e being either 

 added to it, or else the i turned into y. 



But besides the vowel, there is the jod 

 consonant; which, because of its different 

 pronunciation, has likewise a different 

 form, thus, J j. In English it has the 

 soft sound of g, nor is it used but when g 

 soft is required before vowels where g is 

 usually hard : thus we say, jack, jet join, 

 &c. instead of gack, get,goin, &c. which 

 would be contrary to the genius of the 

 English language. 



I, used as a numeral, signifies no more 

 than one, and stands for so many units 

 as it is repeated times : thus I, one ; II, 

 two ; III, three, &c. and when put before 

 a higher numeral it subtracts itself, as 

 IV, four; IX, nine. &c. : but when set 

 after it, so many are added to the higher 

 numeral as there are 1's added : thus VI, 

 is 5-j-l or six? VII, 5+2, or seven ; 

 VIII, 5+3, or eight. The ancient Ro- 

 mans likewise used 13 for 500, CIo for 

 1,000,130 for 5,000, CCIoo for 10,000, 

 lOOO for 50,000, and CCCIooo for 

 100,000. Farther than this, as Pliny ob- 

 serves, they did not go in their notation ; 

 but, when necessary, repeated the last 

 number, as CCClooo, CCCIooo for 

 200,000; CCCIOOO,CCCIooo,CCCIooo 

 for 300,000 ; and so on. 



JACK, in mechanics, an instrument of 

 common use for raising heavy timber, or 

 very great weights of any kind. 



The common kitchen jack is a com- 

 pound engine, where the weight is the 

 power applied to overcome the friction 

 of the parts, and the weight with which 

 the spit is charged; and a steady and 

 uniform motion is obtained by means of 

 the fly. 



JACK, in naval affairs, a sort of flag, or 

 colour, displayed from a staff erected 

 tin the outer end of a ship's bowsprit. In 



the British navy, the jack is a small union 

 flag; but in merchant ships the union IB 

 bordered with red. 



JACK smoke. See SMOKE jack. 



JACK in the box, a large wooden male 

 screw, turning in a female one, which 

 forms the upper part of a strong wooden 

 box, shaped like a frustum of a pyramid. 

 It is used by means of levers passing 

 through holes in it, as a press in packing, 

 and for other purposes. 



JACK block, a block occasionally at- 

 tached to the top-gallant tie, and through 

 which the top-gallant top-rope is reeved, 

 to sway up or to strike the yard. 



JACKALL, in zoology, an animal of the 

 dog kind, with a slender snout. See CA- 

 NIS. 



JACKET cork. See CORK jacket. 



JACOB*s sta^sometimes called a cross- 

 staff, a mathematical instrument to take 

 altitudes at sea, consisting of a brass cir- 

 cle divided into four equal parts by two 

 lines cutting each other in the centre ; at 

 each extremity of either line is fixed a 

 sight perpendicularly over the lines, with 

 holes below each slit for the better disco- 

 very of distant objects. The cross is of 

 course mounted on a stand for use. 



JACOBUS, un ancient gold coin, worth 

 25s. See COIN. 



JACQUINIA, in botany, so named in 

 honour of Nic. Jos. de Jacquin, professor 

 of botany at Vienna, a genus of the Pen- 

 tandria Monogynia class and order. Na- 

 tural order of Dumosx. Sapotse, Jussieu. 

 Essentialcharacter : corolla ten-cleft ; sta- 

 mens inserted into the receptacle ; berry 

 one-seeded. There are four species, na- 

 tives of the West Indies and South Ame- 

 rica. 



JACTITATION of marriage, in law, is 

 when one of the party boasts, or gives out, 

 that he or she is married to the other, 

 whereby a common reputation of their 

 matrimony may ensue. On this ground 

 the party injured may libel the other in 

 the spiritual court ; and unless the defen- 

 dant undertake, and make out a proof of 

 the actual marriage, he or she is enjoin- 

 ed perpetual silence on that head. 



JADE. See NEPHRITE. 



JALAP is the root of the convolvolus 

 jalappa. It derives its name from Xalapa, 

 a town of Mexico, in the environs of which 

 it grows plentifully. It is also fount! 



