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INEBRIANTS, a term derived from 

 the Latin, anr -applied to that class of 

 substances tba i ife.ct the nerves in a par- 

 ticular and agreeable manner,and through 

 them alter and disturb the functions of 

 the mind. They are divided into natural 

 and artificial : the former are chiefly in 

 use among oriental nations; to the latter 

 Europeans have recourse. Natural ine- 

 briants, are opium, in use in Turkey and 

 the East ; peganum harmala, Sirian rue ; 

 of this the seeds are chiefly used : maslac 

 of the Turks, or bangue of the Persians, 

 prepared from the dust of the male flow- 

 er of hemp ; bangue of the Indians, from 

 the leaves of the hibiscus abelmoschus; 

 seeds of various species of the datura, or 

 thorny apple : penang, or betel, of the 

 Indians ; roots of black henbane ; hyos- 

 cyamus physaloides ; berries of the night- 

 shade ; leaves of millefoil ; tobacco. Ar- 

 tificial inebriants are, fermented liquors 

 from farinaceous seeds ; wines and spirits 

 drawn by distillation. See DRUNKEN NESS. 



INERTIA of matter, in philosophy, is 

 defined by Sir Isaac Newton to be a pas- 

 sive principle, by which bodies persist in 

 a state of motion or rest, receive motion 

 in proportion to the force impressing it, 

 and resist as much as they are resisted. 

 It is also defined by the same author to be 

 a power implanted in all matter, whereby 

 it resists any change endeavoured to be 

 made in its state. See MECHANICS. 



All bodies preserve or continue, as of 

 themselves, in their state of rest, or of 

 uniform motion in a right line, in such 

 manner, that a body at rest cannot move 

 without being solicited or urged by some 

 force ; neither can the rectilinear and 

 uniform motion of a body be changed 

 without the action of a foreign cause. 

 That want of aptitude which bodies have, 

 of producing in themsleves a change in 

 their actual state, is called inertia. Now 

 it is known that a body, whose state may 

 Tie changed by the action of a foreign 

 force, cannot give way to that effect, 

 otherwise than by itself altering the state 

 of that force ; that is to say, by itself tak- 

 ing away a part of its motion. It has hence 

 been concluded, that the continuance of 

 a body in its state of repose, or of uniform 

 motion, was itself the effect of a real 

 force which resided in that body ; and 

 ', this force has been viewed, sometimes, as 

 ; a resistance, in so far as it opposed itself 

 to the action of the other force, which 

 changed the state of that body, and some- 

 times as an effort, in so far as it tended to 

 carry with it the change in the state of 

 1 the other force. 



The celebrated Lap lace has proposed a 



more precise and natural manner of con- 

 templating inertia. To conceive in what 

 it consists, suppose a body in motion to 

 meet with a body at rest : it will commu- 

 nicate to it a part of its motion ; in such 

 manner, that if the first have, for example-, 

 a mass double to that of the second, in 

 which case its mass will be two-thirds of 

 the sum of the masses, the velocity which 

 it will retain will be also two-thirds of 

 that which it hadat first; and as the other 

 third, which it has yielded to the second 

 body, employs itself upon a mass of only 

 half the magnitude of the former, the two 

 bodies will both have the same velocity 

 after the shock. 



The effect of inertia is reduced, there- 

 fore, to the communication made by one 

 of these bodies to the other, of a part of 

 its motion; and since this latter cannot 

 receive, butin consequence of the other'a 

 losing, this loss has been attributed to a 

 resistance exercised by the body receiv- 

 ingthe motion. Butin the instance before 

 us, it is very nearly as in the motion of an 

 elastic fluid, contained in a vessel from 

 which we would open a communication 

 to another vessel which should be empty; 

 this fluid would introduce itself by its ex- 

 pansive force into the second vessel, un- 

 til it became uniformly distributed in the 

 capacities of the two vessels : in like man- 

 ner, a body when it strikes another does 

 nothing else, if we may so express our- 

 selves, than pour into this latter a part of 

 its motion ; and there is no more reason 

 to suppose a resistance in this case than 

 in the examples we have just cited. It is 

 true, that, when we strike with the hand 

 a body at rest, or whose motion is less ra- 

 pid than that of the hand, we imagine that 

 we experience a resistance; but the illu- 

 sion proceeds from this, that the - ffect is 

 the same with regard to the hand, as 

 though it were at rest, and was struck by 

 the body with a motion in a contrary di- 

 rection. 



INFAMY, in law, which extends to for- 

 gery, perjury, gross cheats, &c. disables 

 a man to be a witness or a juror ; but a 

 pardon of crimes restores a person's cre- 

 dit, to make him a good evidence. 



INFANCY, the first stage of life. In a 

 medical and political view, extending 

 from birth to about the seventhyear. Like 

 every other stage of life, it is subject to 

 its peculiar diseases, even in the healthi- 

 est state of the constitution, and under the 

 best and most natural control. But from 

 a too generally inherent debility, produc- 

 ed by the common consequences of po- 

 lished and fashionable life, added either 

 to maternal neglect, or a superabundance 



