84 NATURAL HISTORY. 



bodies the native spirit of the body ; and in some other, 

 plain air that is gotten in ; as in bodies desiccate by 

 heat or age : for in them, when the native spirit goeth 

 forth, and the moisture with it, the air with time get- 

 teth into the pores. And those bodies are ever the 

 more fragile ; for the native spirit is more yielding and 

 extensive (especially to follow the parts) than air. 

 The native spirits also admit great diversity ; as hot, 

 cold, active, dull, &c., whence proceed most of the 

 virtues and qualities (as we call them) of bodies : 

 but the air intermixed is without virtues, and maketh 

 things insipid, and without any extimulation. 



Experiment solitary touching concretion and dissolution 

 of bodies. 



843. The concretion of bodies is (commonly) solved 

 by the contrary ; as ice, which is congealed by cold, is 

 dissolved by heat ; salt and sugar, which are excocted 

 by heat, are dissolved by cold and moisture. 1 The 

 cause is, for that these operations are rather returns to 

 their former nature, than alterations ; so that the con 

 trary cureth. As for oil, it doth neither easily congeal 

 with cold, nor thicken with heat. The cause of both 

 effects, though they be produced by contrary efficients, 

 seemeth to be the same ; and that is, because the spirit 

 of the oil by either means exhaleth little ; for the cold 

 keepeth it in ; and the heat (except it be vehement) 

 doth not call.it forth. As for cold, though it take hold 

 of the tangible parts, yet as to the spirits, it doth rather 

 make them swell than congeal them : as when ice is 

 congealed in a cup, the ice will swell instead of con 

 tracting, and sometimes rift. 



I Arist. Meteor, iv. 5. 



