COM 



COM 



stance, combustion must be a rapid union 

 of oxygen with a combustible body; and 

 the heat has been supposed to be given 

 out from the oxygen during 1 a condensa- 

 tion of this last, which, it is imagined, 

 takes place universally in this process. 

 This, however, has not been proved. 



Dr. Thomson, considering caloric and 

 light as distinct substances, has adduced 

 many facts and observations, to prove, 

 that as caloric abounds in oxygen, so 

 light is a component part of every com- 

 bustible. And thence, according to his 

 doctrine, while the base of oxygen 

 combines with the base of the combusti- 

 ble, the caloric of the one and the light 

 of the other unite in the form of fire. 

 From this theory he shows why, in the 

 transitions of oxygen from one combusti- 

 ble base to another, the act of combustion 

 does not take place ; namely, because the 

 caloric of the oxygen has no light pre- 

 sented to it lo combine with. The whole 

 tloctrine, though undoubtedly requiring 

 further developement and proof, is enti- 

 tled to the greatest attention of chemists. 

 See CALOKIC, CAPACITY, CHKMISTRT, 

 HEAT. 



COMBUSTION of living individuals of the 

 human species. Citizen Lair, in 1797, com- 

 municated to the Philomathic Society at 

 Paris, a memoir on the spontaneous com- 

 bustion of human individuals, of which in- 

 stances are related in the Copenhagen 

 Acts of 1692; the Annual Register, 1763 

 and 1775 : the Philosophical Transac- 

 tions, 1744 ; the Observations of Le Cat, 

 1729 and 1749 ; and the Journal de Me- 

 decine for 1779 and 1783 : and to these 

 he has added some others related by per- 

 sons living at Caen, and on the testimony 

 of a surgeon of the same town, who at- 

 tested the circumstances of an event of 

 this description by a verbal process. 



Difficulties would no doubt be offered 

 for reasoning against these facts; but 

 the writer remarks, that human testimo- 

 ny is not to be rejected, unless the pro- 

 bability that the facts must be impossible 

 shall be greater than that arising from the 

 concurrence of evidence ; and he adds, 

 that the narratives, though varying so 

 widely as to time and place, do very re- 

 markably agree in their tenor. The cir- 

 cumstances are, that (1) the combustion 

 has usually detroyed the person, by re- 

 ducing the body to a mass of pulverulent 

 fatty matter, resembling ashes. 2. There 

 were no signs of combustion in surround- 

 ing bodies, by which it could be occasion- 

 ed, as these were little if at all injured; 

 1 hough (3) the combustion did not seem 

 to be so perfectly spontaneous, but that 



some slight cause, such as the fire of a 

 pipe, or a taper, or a candle, seems to 

 have began it. 4. The persons were ge- 

 nerally much addicted to the use of spi- 

 ritous liquors; were very fat ; inmost in- 

 stances women ; and old. 5. The extre- 

 mities, such as the legs, hands, or crani- 

 um, escaped the fire. 6. Water, instead 

 of extinguishing the fire, gave it more ac- 

 tivity, as happens when fat is burned. 7. 

 The residue was oily and fetid ashes, with 

 a greasy soot, of a very penetrating and 

 disagreeable smell. 



The theory of the author may be con- 

 sidered as hypothetical, until maturer ob- 

 servations shall throw more light on the 

 subject. The principal factis, that char- 

 coal and oil, or fat, are known in some in- 

 stances to take fire spontaneously, and 

 he supposes the carbon of the alcohol to 

 be deposited in the fat parts of the hu- 

 man system, and to produce this effect. 



COMEDY, a dramatic poem, represent- 

 ing some event in common life, which is 

 supposed to take place among private in- 

 dividuals. Its object is to ridicule the 

 vices and follies of mankind. 



The unities of action, time and place, 

 the division of the acts, the introduction 

 of episodes,the intermixture of the scenes, 

 are common to both tragedy and comedy. 

 But in other essentials they differ : the 

 one inspires terror and pity ; the other 

 excites gaiety and mirth. The characters 

 in tragedy are, kings, princes, tyrants, 

 heroes ; those in comedy are, ridiculoiib 

 people of quality, cits, valets, gossips, 

 &c. The style also ,of the latter has its 

 peculiar characteristics ; it should be 

 simple, lively, familiar, and replete with 

 sallies of wit, satire, and genuine humour. 



As almost all the rules of dramatic poe- 

 try are constructed with a view to 

 strengthen the resemblance of fiction to 

 reality, they ought in comedy to be most 

 minutely attended to ; because, as the 

 scenes it represents bear a nearer affinity 

 to real life, any defect in the resemblance 

 is more readily discovered. Hence the 

 necessity of truth in the delineation of 

 character, of simplicity in the texture of 

 the intrigue, of spirit and consistency in 

 the dialogue, and of genuine nature in 

 the sentiments. Hence, too, that grand 

 requisite, the art of concealing art, in ma- 

 naging the progressive intricacy of the 

 plot, which constitutes the illusion of 

 theatrical representations. The intrigue 

 of comedy does not consist in the con- 

 struction of a fable barely probable, but 

 in a natural series of familiar events, de- 

 veloped in the most clear and impressive 

 way. It may be of use, therefore, to trace 



