AIR EVERYWHERE. 167 



even the smallest vessel completely of air, as there 

 must always be as much remaining as has spring 

 enough to raise the valve of the pump. 



Then as to touching, if we touched things them- 

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

 gers, 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 jiever 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 ceiling 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. 



If it were not that the air always comes between 



