68 Mayow 



hollow of the cupping-glass by the pressure of the sur- 

 rounding air. But now let us inquire why the space 

 within the cupping-glass becomes almost empty 

 immediately upon the extinction of the flame. One 

 might readily say here that the fiery and aerial par- 

 ticles are agitated in the flame with a very rapid motion 

 and are much rarefied, but that after the extinction of 

 the flame they cease from their movement and are con- 

 densed, so that these particles are no longer able to 

 resist the pressure of the surrounding air. But this 

 answer does not seem quite satisfactory, for it is prob- 

 able that air is largely mixed with the flame, since it 

 supplies it with nutriment, so that not even the 

 smallest part of the flame is altogether destitute of air. 

 But if the air were distributed abundantly enough in 

 the flame, it does not appear that it would be condensed 

 after the extinction of the flame to the extent required 

 for rendering the space in the cupping-glass so empty. 



Wherefore I think it should be maintained that the 

 air mixed with the flame is, by the burning of the 

 flame, quickly deprived of its nitro-aerial and elastic 

 particles, so that this air not only becomes unfit for 

 sustaining fire but also loses in part its elasticity. 

 Hence when a flame enclosed in a glass vessel has 

 exhausted the nitro-aerial particles of the air, it soon 

 goes out and the space contained within is like a 

 vacuum, not only on account of the diminished motion 

 of the igneous particles, but partly also from the lack 

 of elastic particles, as will appear more evident from 

 the following experiments. 



For instance, let a burning candle be placed in water 

 so that the wick may stand about six finger-breadths 

 above the water, and then let an inverted cupping- 

 glass of sufficient height be put over the light and 

 plunged immediately into the water surrounding the 



