CENTURY II. 105 



the percussion of the one towards the other differeth 

 as a blow differeth from a cut. 



188. In speech of man, the whispering, which 

 they call &quot; susurrus&quot; in Latin, whether it be louder 

 or softer, is an interior sound ; but the speaking out 

 is an exterior sound ; and therefore you can never 

 make a tone, nor sing in whispering ; but in speech 

 you may : so breathing, or blowing by the mouth, 

 bellows, or wind, though loud, is an interior sound ; 

 but the blowing through a pipe or concave, though 

 soft, is an exterior. So likewise the greatest winds, 

 if they have no coarctation, or blow not hollow, give 

 an interior sound; the whistling or hollow wind 

 yieldeth a singing, or exterior sound ; the former 

 being pent by some other body ; the latter being 

 pent in by its own density : and therefore we see 3 

 that when the wind bloweth hollow, it is a sign of 

 rain. The flame, as it moveth within in itself or is 

 blown by a bellows, giveth a murmur or interior 

 sound. 



189. There is no hard body, but struck against 

 another hard body, will yield an exterior sound 

 greater or lesser : insomuch as if the percussion be 

 over-soft, it may induce a nullity of sound; but never 

 an interior sound ; as when one treadeth so softly 

 that he is not heard. 



190. Where the air is the percutient, pent or 

 not pent, against a hard body, it never giveth an 

 exterior sound ; as if you blow strongly with a 

 bellows against a wall. 



191. Sounds, both exterior and interior, may be 



