NOVUM ORGANUM 165 



from its rapid conversion into vapor, does not so well exhibit 

 the expansion of water in its own shape, while red-hot iron 

 and the like are so far from showing this progress, that, on 

 the contrary, the expansion itself is scarcely evident to the 

 senses, on account of its spirit being repressed and weakened 

 by the compact and coarse particles which subdue and re 

 strain it. But the thermometer strikingly exhibits the ex 

 pansion of the air as being evident and progressive, durable 

 and not transitory. 41 



Take another example. Let the required nature be 

 weight. Quicksilver is a conspicuous instance of weight; 

 for it is far heavier than any other substance except gold, 

 which is not much heavier, and it is a better instance than 

 gold for the purpose of indicating the form of weight; for 

 gold is solid and consistent, which qualities must be referred 

 to density, but quicksilver is liquid and teeming with spirit, 

 yet much heavier than the diamond and other substances 

 considered to be most solid; whence it is shown that the 

 form of gravity or weight predominates only in the quantity 

 of matter, and not in the close fitting of it. 42 



XXV. In the fourth rank of prerogative instances we 

 will class clandestine instances, which we are also wont to 



41 Bacon was not aware of the fact since brought to light by Romer, that 

 down to fourteen fathoms from the earth s mean level the thermometer remains 

 fixed at the tenth degree, but that as the thermometer descends below that 

 depth the heat increases in a ratio proportionate to the descent, which happens 

 with little variation in all climates. Buffon considers this a proof of a central 

 fire in our planet. Ed. 



42 All the diversities of bodies depend upon two principles, i.e., the quantity 

 and the position of the elements that enter into their composition. The primary 

 difference ia not that which depends on the greatest or least quantity of ma 

 terial elements, but; that which depends on their position. It was the quick 

 perception of this truth that made Leibnitz say that to complete mathematics it 

 was necessary to join to the analysis of quantity the analysis of position. Ed. 



