1 2 £)f tlje ^ec&antcal 2D?tgtne 



ther fluids) and coofequently change 

 places and yet the continuity of 

 the whole is not imirely broken, but 

 every corpufcle does fomewhere 

 touch fome other corpufcle and 

 thereby maintain the cohefion that 

 indifpofes it for that intire reparation 

 accompanied with a motion upwards 

 that we call ^volation. And fo^ 

 when Salt- peter alone, is in a Cruci- 

 ble expofed to the fire, though a ve- 

 ry moderate degree of it will fuffice 

 to bring the Salt to a ftate of fufion, 

 and confequently to put the corpu- 

 fcles that compofe it into a reftiefs 

 motionj yet a greater degree of heat, 

 than is ne'ceflary to melt it, will not 

 extricate fo much as the Spirits., and 

 make them fly away. 



CHAP. III. 



pH E foregoing Do&rine of the 

 L Volatility of bodies may be 

 as well illuftrated as applied, if we 

 proceed co deduce from it the gene- 



rall 



