NOVUM ORGANUM. 105 



Fourteenth negative to the ninth affirmative. 



To the instances of warm liquids we may subjoin the 

 negative one of the peculiar nature of liquids in general. 

 For no tangible liquid is known that is at once warm in its 

 nature and constantly continues warm ; but their heat is 

 only superinduced as an adventitious nature for a limited 

 time ; so that those which are extremely warm in their 

 power and effect, as spirits of wine, chymical aromatic oils, 

 the oils of vitriol and sulphur, and the like, and which 

 speedily burn, are yet cold at first to the touch, and the 

 water of natural baths, poured into any vessel and sepa 

 rated from its source, cools down like water heated by the 

 tire. It is however true that oily substances are rather less 

 cold to the touch than those that are aqueous, oil for in 

 stance than water, silk than linen ; but this belongs to the 

 table of degrees of cold. 



Fifteenth negative to the tenth affirmative. 



In like manner we may subjoin a negative instance to 

 that of warm vapour, derived from the nature of vapour it 

 self; as far as we are acquainted with it. For exhalations 

 from oily substances, though easily inflammable, are yet 

 never warm unless recently exhaled from some warm sub 

 stance. 



Sixteenth negative to the tenth affirmative. 



The same may be said of the instance of air. For we 

 never perceive that air is warm unless confined or pressed, 

 or manifestly heated by the sun, by fire, or some other 

 warm body. 



Seventeenth negative to the eleventh affirmative. 



A negative instance is exhibited in weather by its cold 

 ness with an east or north wind, beyond what the season 

 would lead us to expect ; just as the contrary takes place 

 with the south or west winds. An inclination to rain (espe 

 cially in winter) attends warm weather, and to frost cold 

 weather. 



Eighteenth negative to the twelfth affirmative. 



A negative instance as to air confined in caverns may be 

 observed in summer. Indeed we should make a more dili 

 gent inquiry into the nature of confined air. For in the 

 first place the qualities of air in its own nature with regard 

 to heat and cold, may reasonably be the subject of doubt. 

 For air evidently derives its heat from the effects of celestial 

 bodies, and possibly its cold from the exhalation of the 

 earth, and in the mid region of air (as it is termed) from 

 cold vapours and snow, so that no judgment can be formed 

 of the nature of air by that which is out of doors and ex- 



