314 PRESSURE IK THE Alfc, 



things, actually were what it actually is not ; 

 the various estimates which I have above de- 

 tailed, might then be applied. Mr. Cote's cal- 

 culation might be true, that the circumambient 

 air, was in weight, upon the surface of the 

 earth, equal to a leaden globe 60 miles in dia- 

 meter ; and that \he weight of 15,370 Ibs. pres- 

 sed on our frail and debile bodies. It must, 

 however, be evident, that a weight such as this, 

 would lacerate to atoms the lungs of all ani- 

 mated beings ; and explode every part of the 

 system to which it obtained admission that 

 the fluids would be pressed and squeezed out 

 of the exhalent vessels, and that air would 

 issue out of every pore.* So far, therefore, 

 from measuring by its weight, the degree of 

 pressure which the atmosphere exerts, it is 

 by its expansibility alone, that its effects are 

 produced, pressing with the greatest force 

 when it is least ponderable, and when it is 

 most ponderable, Exerting the least pressure; 

 that is to say, air is most expansible when least 

 ponderable ; and least ponderable, when most 

 expansible. That this is the fact will appear, 

 if we proceed to ascertain the relative weights 

 of equal volumes of atmospheric air, when they 



* I beg to have it understood, that these calculations are not 

 my own, but those of others, which I offer in order to show 

 how true conclusions can be drawn from false principles, and 

 error substituted for truth. 



