35 i NATURAL HISTORY. 



ration ; for much of the matter of hair, in the other 

 parts of the body, goeth forth by insensible perspi 

 ration, and besides, the skull being of a more solid 

 substance, nourisheth and assimilateth less, and 

 excerneth more, and so likewise doth the chin. We 

 see also, that hair cometh not upon the palms of the 

 hands, nor soles of the feet ; which are parts more 

 perspirable. And children likewise are not hairy, 

 for that their skins are more perspirable. 



Experiment solitary touching the quickness of 

 motion in birds. 



681. Birds are of swifer motion than beasts ; for 

 the flight of many birds is swifter than the race of 

 any beasts. The cause is, for that the spirits in birds 

 are in greater proportion, in comparison of the bulk 

 of their body, than in beasts : for as for the reason 

 that some give, that they are partly carried, whereas 

 beasts go, that is nothing, for by that reason swim 

 ming should be swifter than running : and that 

 kind of carriage also is not without labour of the 

 wing. 



Experiment solitary touching the different clearness 

 of the sea. 



682. The sea is clearer when the north wind 

 bloweth, that when the south wind. The cause is, 

 for that salt water hath a little oiliness in the sur 

 face thereof, as appeareth in very hot days : and again, 

 for that the southern wind relaxeth the water some 

 what ; as no water boiling is so clear as cold water. 



