1807.] 



of the Ph^yfwlogy of 4ristolle. 



545 



ing to nature. For that wlilch is con- 

 trary, implies the prior exllleiice of that 

 which is accorchng to nature. The body 

 thcietore, which is moved with a violent 

 motion, lias Tome natural motion prior to 

 this. Hence, it' the heavenly bodies have 

 always been moved by violence, they 

 have always been moved contrary to na- 

 ture, at the fame time polVeiruig a natural 

 motion, which has never been exerted, 

 but perpetually counteracted. God and 

 nature, however, do nothinn; in vain. If 

 this argument be admitted, tlie centripe- 

 tal and centrifugal H-'orces, which, like the 

 Aloidai, have with giant-pride fo long in- 

 vaded the heavens, w-ill be van(iui(lied by 

 it, ar>d hurled into the fublunary realms. 



The next dogma of Arillotle, to whicli 

 I fliall requell the attention of the reader, 

 is the manner in which the celeitial bo- 

 dies, and efpecially the fun, heat fub- 

 lunary bodies, without being themfelves 

 hot. Previous to this, however, it is ne- 

 ceffary to obferve, that the fun, and each 

 of the other planets, is fixed in a lumin- 

 ous fphere concentric with the earth, in 

 which fphere alfo it is carried round the 

 earth. Thefe fpheres, however, accord- 

 ing to Arifiotle, are not hard impenetra- 

 ble bodies like glafs, as they have been 

 fuppofed to be by Bacon, Newton, and 

 other modern philofophers ; but being of 

 a nature totally dillintt from every ilib- 

 lunary body, they wholly conhft of a 

 matter fo pure and impaflive, that com- 

 pared with fublunary matter, it may be 

 laid to be immaterial. Hence thefe 

 fpheres pervade through each other with- 

 out impediment, like the light emitted from 

 dilYerent lamps in the iiiine room ; and 

 tiie planets which are carried in them, 

 are of a fimilar nature, though not fo 

 tranfcendently pure. 



The rays then jiroceeding from the 

 folar body, pafs through a celeftial to a 

 fublunary body. And through a celeftial 

 body indeed, as being immaterial, tliey 

 penetrate immaterially, and without im- 

 pediment; but they no longer thus pro- 

 ceed through a fublunary body, becaufe 

 this is material. The folar rays, however, 

 penetrate throntrh the pores of the air, 

 and arc rcilccied from folids at equal 

 angles. The air, therefore, being inter- 

 cepted by thefe rays, and at the fame 

 time moveil and rubbed againll itfelf, is 

 in confequencc of its conglobation heat- 

 ed ; and ef|)eciully in ihofe places in which 

 the rays being retlected to tiiemfclvcs iu- 

 fpiffate the intermediate aii-. On this 

 account, of tlie folllices, that of the fum- 

 jiifjf is hotter, not bccaule at that time 



the fun is in reality nearer to u?, fmce he 

 is nearly always at an equal dillauce 

 from us; but becaufe he then approxi- 

 mates to us in power. For his rays, ac- 

 cording to the meridian and about it, are 

 efpecially reflerted into themfelves, and 

 on this account, caufc the intercepted 

 , air to be conglobed and comprelfed. 

 But in whiter, the fun through the day 

 cxifting at the eall and the ueil, the rays 

 omitted to our part of ttic globe, arc no 

 longer fimihuly reflef-ted into themfelves, 

 but being more diHulcd do not (iniilarly 

 comprcfs the air. Hence alfo mountains 

 are colder than plains, becaufe with the 

 reflection the rays are more colleftcd, 

 and more comprcfs the air; but proceed- 

 ing upwards, they become more diftant. 

 On this account alfo, the more elevated 

 air is colder. In Ihort, if ignition begun 

 from on high through motion, it would 

 be nccelfary that places more elevated 

 ihould be hotter, as being nearer to the 

 bodies that are moved. 



The third dogma of Arillotle, vhich 

 appears to me very important, and at the 

 fame time has not been underftood by 

 modern phllofopliers, is that the fummit 

 of the aerial region proximate to the 

 heavens conlilis of injiammable matter. 

 This is called by Arillotle v7nx.y-ci,vu.ei, 

 and according to him is not properly 

 fire, but is only to be fo denominated 

 metaphorically, from its miniftrant office. 

 Hence, fiiys ()lyinpiodorus, it is called 

 i/TTixy.a.viJ.a, from burnhp; lejs; for the 

 addition of the Ltto, implies diminution. 

 Such an infJammable matter, though in- 

 vifible to the naked eve, may perhaps 

 occafion thofe appearances of fpot-i ia 

 thf fun* which are vifible through a te- 

 lefcope. 



In the fourth place, Arifiotle fljows in 

 the fird book of his r^Ieteors. that in very 

 extended periods of time, the continent 

 becomes fea, and the fea becomes con- 

 tinent. This, however, happens in con* 

 fequence of what is called the great ain- 



■ — c: ' ■ — ■ r~ 



* We do not Ice the ftars themfelvej ; for 

 we neither lee their magnitude, nor their fi- 

 gures, nor their furpalVing bejiity. But we 

 fee, as it \*ete, fuch an illumination of them, 

 as that of the light of the fun aiout the 

 earth, the fun himfelf nut being feen by us. 

 Anxl this is perh.ips, what Heraditus meant, 

 when in obfcure language he faid, ffieaking 

 of the fun, " Kindling mcafures and cxtin- 

 guifhing meafures.'' For the fun when he 

 rifcs may he conceived to kindle an image o^ 

 himfelf in the inflammable matter at the 

 fummit of the aerial regiou ; which image 

 bscomcs extini;uhhed when he fcts. 



tei;. 



