AIR EVERY WHERE. 167 



selves, and not the air, they would stick to our 

 fingers, or our fingers would stick to them. The 

 mean pressure of the air is about fifteen pounds 

 on every square inch of surface ; and so, if even 

 the strongest man were to grasp a stick without 

 air between it and his hand, he would never be 

 able to unclasp his hand and let it go. As little 

 could a man walk if there were no air between his 

 feet and the ground. If there were no air, each 

 foot of a full-grown man, if the sole were entirely 

 on the ground, would be pressed to the ground by 

 a weight of about four hundred pounds ; and thus 

 the man could never lift a foot, but would stand 

 on the earth, as still as an earth-fast stone. 



The little ridges of papillae that are on the palm 

 and fingers of a healthy hand, and also on the 

 sole of a well-kept foot, contribute to the ease with 

 which the hands and the feet can be separated 

 from that which they touch, by the air that is 

 lodged in the little hollows between ; and though 

 by close squeezing the sides of the fingers may be 

 made to stick together, the fronts or tips of the 

 fingers never can. 



If there were not atmospheric air in the inter- 

 stices between all substances, nothing which had 

 a base, or surface, of any size that could be placed 

 in contact with another, would fall. In that case, 

 a man would not need to hang his hat on the 

 peg ; he would only need to push it to the wall, 

 and it would remain there. So also he might 

 stick himself to the wall, or lie down on the ceil- 

 ing on his back and look down on the company 

 below. Indeed, it would signify but little where 

 he lay down ; for be it where it might, assuredly 

 he would never be able to rise up again. 



