120 Mayoiv 



fashioned by the supreme Artificer with truly mar^ 

 vellous skill, so as to be naturally adapted for throw- 

 ing each other into a motion of extreme velocity. 

 Indeed, not only in the burning of fire but in produc- 

 ing most natural movements, we must assume as 

 much skill and careful fitting of the mutually adapted 

 particles, as in automata constructed with the most 

 accurate human art. If any one should think that in 

 explaining spontaneous movements of this kind I am 

 having recourse to things too minute, I reply that it 

 is nature's way to produce all the greatest things by 

 means of the least, for how small and delicate are 

 those spirituous particles which set the huge machinery 

 of the elephant in truly stupendous motion ? And 

 what is to be said of the very small particles of 

 insects ? For as their whole bulk is merely a point in 

 appearance, how minute must those portions be which 

 we cannot suppose to be one-thousandth part of the 

 whole ? Indeed I make bold to affirm that natural 

 movements of this kind are effected by particles too- 

 minute for human discernment. 



It is to be concluded from the foregoing that the 

 ignited particles in the burning of fire are agitated 

 with elastic impulse, for just as we have shown above 

 that the power of recoil in bent rigid bodies is due to 

 the pulsation of subtle matter, so also we maintain that 

 the motion of ignited particles results from impact of 

 the same matter. Indeed the burning of fire does not 

 seem to be very different from the bending to fracture 

 of any rigid body, or rather of the aforementioned 

 glass drops. For as in bent rigid bodies, their particles^ 

 thrust within the circles of the subtle matter, are 

 struck by it, and at last, if the rigid body is bent to 

 breaking, are violently driven out, so in fire the 

 sulphureous and nitro-aerial particles, when they enter 



