xv ANALOGY FROM HUMAN BODY 127 



of sulphur, too, may solidify the moisture, lasting 

 for a longer or shorter time. Therefore, as in our 

 bodies, when a vein is cut, the flow of blood lasts 

 till the blood is exhausted or the incision in the 

 vein has closed up and stopped it, or until some 

 other cause has staunched the blood ; in like manner 

 in the ground, when the seams have been loosened 

 and laid bare, a stream or river rushes forth. The 6 

 way in which the water is used up depends on the 

 extent of the opening in the seam. At one point 

 its flow is checked by some obstacle ; at another it 

 heals up, so to speak, into a scar and chokes the 

 path it had made ; at another the power of trans 

 mutation, which we have said the earth possesses, 

 reaches its limit and cannot longer supply material 

 that may be liquefied : sometimes the exhausted 

 source is replenished, now by energy self-recruited, 

 now by a supply drawn from external sources. For I 

 ought to say that often dry objects placed opposite 

 to wet attract the moisture to them. Earth itself, 7 

 which easily assumes another form, often wastes 

 away, and is dissolved in moisture. The same 

 phenomenon occurs under the earth as above it in 

 the clouds ; becoming too dense and heavy to retain 

 longer its own character, solid begets liquid. There 

 is often a gathering of thin, scattered moisture like 

 dew, which from many points flows into one spot. 

 The dowsers call it sweat, because a kind of drop 

 is either squeezed out by the pressure of the ground 

 or raised by the heat. This slender trickle scarce 

 suffices to form a spring. But if the sources are 

 great and the gatherings great, rivers issue. Some 

 times they flow gently if the water merely descends 

 by its own weight, sometimes with violence and 

 loud roar if air be intermingled and eject the water. 



