XOVUM ORGAXUM. 107 



Twenty-second negative to the sixteenth affirmative. 



We are of opinion that here again there is no negative. 

 For we are not acquainted with any tangible body which 

 does not become decidedly warm by friction, so that the 

 ancients feigned that the gods had no other means or power 

 of creating heat than the friction of air, by rapid and violent 

 rotation. On this point, however, further inquiry must be 

 made, whether bodies projected by machines (as balls from 

 cannon) do not derive some degree of heat from meeting the 

 air, which renders them somewhat warm when they fall. 

 The air in motion rather cools than heats, as in the winds, 

 the bellows, or breath when the mouth is contracted. The 

 motion, however, in such instances is not sufficiently rapid 

 to excite heat, and is applied to a body of air and not to its 

 component parts, so that it is not surprising that heat should 

 not be generated. 



Twenty-third negative to the seventeenth affirmative. 



We must make a more diligent inquiry into this instance. 

 For herbs, and green and moist vegetables appear to possess 

 a latent heat, so small however as not to be perceived by 

 the touch in single specimens, but when they are united 

 and confined, so that their spirit cannot exhale into the air, 

 and they rather warm each other, their heat is at once ma 

 nifested, and even flame occasionally in suitable substances. 



Twenty-fourth negative to the eighteenth affirmative. 



Here too we must make a more diligent inquiry. For 

 quick lime, when sprinkled with water, appears to conceive 

 heat, either from its being collected into one point (as we 

 observed of herbs when confined), or from the irritation 

 and exasperation of the fiery spirit by water, which occasions 

 a conflict and struggle. The true reason will more readily 

 be shown if oil be used instead of water, for oil will equally 

 tend to collect the confined spirit, but not to irritate. The 

 experiment may be made more general, both by using the 

 ashes and calcined products of different bodies, and by 

 pouring different liquids upon them. 



Twenty-fifth negative to the nineteenth affirmative. 



A negative instance may be subjoined of other metals 

 which are more soft and soluble. For leaf gold dissolved 

 by aqua regia, or lead by aqua fortis, are not warm to the 

 touch whilst dissolving, no more is quicksilver (as far as I 

 remember), but silver excites a slight heat, and so does 

 copper, and tin yet more plainly, and most of all, iron and 

 steel, which excite not only a powerful heat but a violent 

 bubbling. The heat therefore appears to be occasioned by 

 the struggle which takes place when these strong dissolvents 



