NOVUM OROANUM 121 



such a plan, and in such order that the understanding may 

 be enabled to act upon them. 



Even when this is done, the understanding, left to itself 

 and to its own operation, is incompetent and unfit to con 

 struct its axioms without direction and support. Our third 

 ministration, therefore, must be true and legitimate induc 

 tion, the very key of interpretation. We must begin, how 

 ever, at the end, and go back again to the others. 



XI. The investigation of forms proceeds thus: a nature 

 being given, we must first present to the understanding all 

 the known instances which agree in the same nature, al 

 though the subject matter be considerably diversified. And 

 this collection must be made as a mere history, and without 

 any premature reflection, or too great degree of refinement. 

 For instance; take the investigation of the form of heat. 



Instances agreeing in the Form of Heat 



1. The rays of the sun, particularly in summer, and at 

 noon. 



2. The same reflected and condensed, as between moun 

 tains, or along walls, and particularly in burning mirrors. 



3. Ignited meteors. 



4. Burning lightning. 



5. Eruptions of flames from the cavities of mountains, etc. 



6. Flame of every kind. 



7. Ignited solids. 



8. Natural warm baths. 



9. Warm or heated liquids. 



10. Warm vapors and smoke; and the air itself, which 

 admits a most powerful and violent heat if confined, as in 

 reverberating furnaces. 



