INFLUENCE ON RECENT SCIENCE 91 



and the stars are not this pure elemental fire but merely 

 heated matter of a terrestrial nature. Such havoc does 

 experiment play with a grandiose hypothesis. We 

 may, however, pass over difficulties impossible to have 

 been foreseen by Descartes, since many men of science 

 still think an hypothesis valuable if it escapes con- 

 temporaneous troubles, and of these there are always 

 an abundance. 



Between these star centers lie the great interstellar 

 spaces which some believe to be vacuous but which 

 Descartes supposes are packed with matter of the sec- 

 ond kind. The interstices, which would otherwise 

 exist between these little spheres, are filled with matter 

 of the first kind. And all together they rush around 

 common axes to form the vast heavenly vortices with 

 a velocity enormous but less than that of the celestial 

 fire of the stars. 



This accounts for all the universe except those parts 

 occupied by terrestrial and planetary bodies, which 

 are composed mostly of matter of the third kind. The 

 constituent parts of this kind of matter, as stated be- 

 fore, consist of agglomerated masses of the other two 

 kinds, whose pores are filled with matter of the first 

 and second kinds still in their simple state. Accord- 

 ing to the relative proportions and various arrange- 

 ments of these three constituents, we distinguish all the 

 different bodies which are classed as solids, liquids, 

 and gases. Of these, solid bodies are those whose least 



