QUA 



QUA 



QuALlTlKs, Corporeal or Phyfical, are what we chiefly 

 coiiiider under this di nominatioii, and to wliich the defini- 

 tion above hiid down is accommodated. 



Philoiophirs arc divided as to the nature of thefe qualities, 

 or what they are in the body. The general language of 

 the Peripatetic fchool is, that they are things diftinft from 

 the bodies thcmfelves ; and are fuperadded to them, or flow 

 from their fubftantial forms : on which principle, they hold 

 qualities to be real, and denominate them acc'uUnts ; fup- 

 pofing them to be inherent in fubllances, though not in the 

 relation of parts, but to be fuftained by them as in a fubjedl, 

 and incapable of lubfifting without them. In effeft, the 

 Thomills define qualities to be accidents following or arifing 

 from the form ; in the fame manner as quahty is an accident 

 foUowinsr or arifina; from the lubftance. 



The moderns abfolutely explode the notion of qualities 

 dillinft from the body ; and infiil, that the powers by which 

 bodies excite in us the ideas of fuch qualities, are no other 

 than the mechanical affedtions of the bodies themfelves, viz. 

 the figure, magnitude, ir.otion, &c. of the parts of which 

 they coiifift. 



The principal confiderations infilled on by the retainers to 

 real qualities are, that thefe powers may be aftually feparated 

 from the fubllances they inhere in ; as we fee in light, heat, 

 &c. That from thefe very qualities, confidered as fo many 

 determinations, tliere arifes a very great diverfity in bodies ; 

 and that bodies, according to the diverfity of their qualities, 

 affeftour fenfes very differently. 



The adherents to the experimental way, on the contrary, 

 account for all the qualities of bodies from mechanical 

 caufes. Thus all tlie phenomena of a clock, the motion of 

 its wheels, its hands, &c. by which it llrikes the hour, points 

 the minute ; day, moon's age, &c. do all evidently arife from 

 the fingle fpring ; which we never imagine to have any par- 

 ticular powers by which it (hould be enabled to make fuch 

 difcoveries ; nor any other principle but that one of elalticity. 

 Why, then, may we not conceive, as- to fenfible qualities, 

 that though, by virtue of a certain congruity or incongruity 

 in point of figure, texture, or other mechanical properties, 

 the portions of matter they modify are enabled to produce 

 various effefts, on account of which the bodies are faid to 

 be endowed with qualities ; yet thefe are not, in the bodies 

 endowed with them, any real or diftinft entities, or differing 

 from the matter itfelf of fuch a determinate bignefs, Ihape, 

 and other mechanical modifications? Thus, though the 

 modern goldfmiths and refiners reckon it among the moft 

 diftinguifhed qualities of gold that it is diffoluble in aqua 

 regia, whilft aqua fortis will not work upon it ; yet thefe 

 attributes are not ii the gold any thing diftinft from its 

 peculiar texture ; nor is the gold we have now of any other 

 nature than it was in Pliny's time, when aqua fortis and 

 aqua regia were unknown. 



We all know that the fun hath a power to harden clay, 

 foften wax, melt butter, thaw ice, turn water into vapour, 

 make air expand itfelf in weather-glafFes, contribute to 

 blanch linen, render the white llcin of 'the face fwarthy, and 

 mowed grafs yellow, ripen fruit, hatch the eggs of filk- 

 worms, caterpillars, &c. apd perform many other things, 

 fome of which feem contftry to others ; yet thefe are not 

 diilinft powers, or faculties in the fun, but only the pro- 

 duftioa of its heat, diyerfified by the different textures of 

 the body it chances to work on, and the condition of the 

 other fubftances concerned in the operation. And, there- 

 fore, whether or not the fun, in fome cafes, has any influence 

 at all diilindt from its light and heat, we fee that all the 

 pheiiomena mentioned are producible by the best of comipon 



fire, duly applied and regulated. Some of the ancicnte, 

 and particularly the Peripatetics, have diftinguifhed qualities 

 into fenji/i/e and accull. 



QUALITIES, Senfiblc, or Manifejl, are thofe arifing from 

 certain modifications of matter, and which become imme- 

 diately the objedts of our fenfes. Such are all thofe above- 

 mentioned. 



Though, in ftriftnefs, thofe only are faid to be fenfible 

 qualities which affcft fome one fenfe alone ; as colour does 

 the eye, found the car, &c. 



Thefe are fometimes, alfo, called tangible qualities, becaufe 

 they only produce their effeft, /'. e. excite their idea in us, 

 when contiguous, or in contaft with the organ. 



Qualities, Occult, are certain latent powers arifing from 

 the fpecific forms of things, of which no rational folution 

 can be given on any principles of phyfics. 



Senfible qualities are ufually fubdivided into primary and 

 fccondary. See Ideas. 



Qualities, Primary, or General, are fucTi as are found 

 in all bodies ; or which agree to all matter, confidered as 

 matter, and therefore to the elements themfelves. Such are 

 extenfion, figure, motion, reft, folidity, impenetrability, and 

 number. 



Qualities, Secondary, or FarlicuJar, are fuch as refult 

 from a compofition or mixture of elements, and do not 

 agree to body as body, but as a mixt. Such are light, heat, 

 cold, colour, found, talle, fmell, hardnefs, foftnefs, fluidity, 

 firmnefs, roughnefs, fmcothnefs, opacity, tranfparency, &c. 



According to Ariftotle, and the Peripatetics, the primary, 

 or elementary qualities, are thofe of the four element* 

 themfelves ; w'z. heat, cold, moifture, and drynefs. 



The fecondary qualities, according to the fame, are all 

 the reft ; which are combinations or affemblages of the 

 former elementary ones ; as colour, odour, tafte, &c. 



To give an idea of Ariftotle's method of accounting 

 for thefe fecondary qualities from thefe primary ones, we 

 fhall inftance in his account of colour. All colours, then, 

 fays he, are generated of a mixture of the four elementary 

 qualities : white, e. gr. is produced when the humidity fur- 

 mounts the heat, as in old men, whofe hair grows grey ; 

 black is produced when the humidity dries off, as in walls, 

 cifterns, &c. red, &c. 



Among the fchool-philofophers we meet with other di\n. 

 fions of quaUties ; as adive, iud paj^ve ; real, and intentional. 



Qualities, j43ive, are thofe by virtue of which effefts 

 and operations are aftually produced on other bodies duly 

 difpofed with refpeft to them. Such are the heat of fire, 

 the moifture of water, &c. 



Qualities, Pajfive, are thofe by which bodies are dif- 

 pofed to receive the aftion of others. Such are inflamma- 

 bility in oil, &c. 



Qualities, Real, are thofe which remain in the fubjeft, 

 and only aft on things adjacent to it. As fire in a piece of 

 iron not ignited, &c. 



Qualities, Intentional, are thofe which iffue from the 

 fubjeft, and operate at a diftance. Such is the light emitted 

 from the fun, Sec. 



But the moderns are agreed, that either all quahties are 

 real, or all alike intentional. So that the diilinftion is im- 

 pertinent. See on the fubjeft of quality, its various fpecies, 

 and its different properties, Harris's Philofophical Arrange- 

 ments, chap. viii. 



However ignorant we ma)' be of the nature of qualities, 

 or of the manner of their operation, yet we know the laws 

 of their intention and rennffion. Dr. Keil demonftrates, 

 that every quality which is propagated in orbcm, fuch as 



light, 



