of the Law of Mariotte, with Corrections^ Sfc. 339 



the reason for a variation is manifest, and its law is seen 

 from the above corollary, which is the proof of the 2nd 

 prop, in the paper. 



Cor, 2. During an increase of compression, ethereal 

 atoms will be continually given out from the inner vessel, 

 and during a diminution of pressure they will be absorbed. 



Cor, 3. After a certain limit of pressure, two adjacent 

 tenacious atoms will enter at once into union. 



For, although the atmospherules of the tenacious atoms 

 are more dense as we approach the surfaces of repulsion, 

 yet, when these surfaces, after contact, intersect each other, 

 the atmospherules will begin to be repelled from the line 

 immediately between the centres ; hence, a limit to an 

 increase of assistance from intervening ethereal atoms will 

 be attained, and union of the tenacious atoms will occur 

 on a small additional pressure, for this effect will be pro- 

 moted by the pressure, and the greatly increasing attraction 

 of the atoms. 



Cor. 4. Hence, when a gas liquifies by compression, the 

 main body of the gas will become liquid at once. 



For, in common circumstances, since the pressure is 

 nearly the same throughout the vessel, the point of equi- 

 librium will be attained very nearly at the same time in 

 every part of the vessel. 



Cor, 5. A little before liquifaction the ratio of the com- 

 pression to the density will diminish. 



For, when the equilibrium is just attained, the operation 

 of the law ceases, since the ethereal atoms begin to be 

 removed from the line joining the centres, and the resist- 

 ance diminishes. 



Cor, 6. The resistance to compression will be much 

 greater in liquids than in gaseous bodies, and will follow a 

 different law. 



For, the repulsion between tenacious is vastly greater 

 than between ethereal atoms; and the resistance in this 

 case does not depend on the pressure at T. 



Cor, 7. When a gas becomes a liquid, abundance of 

 ethereal matter will be evolved ; and the converse. 



Cor, 8. The compressing force varies inversely as the 

 volume, because the density varies in that ratio. 



Scholium 2. That the density of air varies as the com- 



z 2 



