204 SPECULATIVE SCIENCE 



acknowledgment which we can find) the best of Hobbes's ideas, 

 without being able to leave the dross behind. Hobbes has a 

 kind of undulating theory of light, which he thought was pro- 

 duced by the motion of an ether ; Leibnitz took that too ; but 

 Galileo might perhaps claim this, as well as the notion that it 

 was the action of this ether which was meant by the spirit 

 brooding on the waters at creation. Leibnitz took that too, and 

 altogether he seems to have been a great hand at appropriation. 

 Malebranche, who followed Descartes in most things, gave 

 up to a great extent the balls and dust and snakes, and broached 

 the idea that gross matter was made up of molecules, each of 

 which was an eddy or vortex of the primeval fluid. Here we 

 reach an intelligible conception, greatly in advance of the crude 

 and somewhat confused views of Hobbes. The molecule is 

 separated from the surrounding medium by the motion of its 

 parts, it has a distinct existence, and may have very different 

 properties from all the rest of the medium or fluid. If the parts 

 of this fluid do not cohere in any way, but move frictionless, 

 our little vortex-atom may have quite a sharp boundary, and if 

 inertia be granted as an original property in our fluid, the little 

 vortex may go on spinning for ever. Moreover, if it goes at a 

 very great rate it may contain almost infinitely more energy 

 or power than other parts of the medium, even when these are 

 displaced by the motion of the vortex-atom, or a congeries of 

 these, through the medium, which must of course then form a 

 comparatively slow eddy coming in behind our vortex-atoms as 

 fast as it is shoved away in front. The vortex plays the part of 

 the Lucretian atom, the medium of the Lucretian void. A few 

 vortices in a given space constitute a rare body ; a dense body 

 contains many vortices in the same space. The idea is one of 

 remarkable merit, and has received several recent developments. 

 Malebranche conceives the medium itself as full of vortices, 

 almost infinitely small as compared with those constituting 

 gross matter. He thought that cohesion was the result of 

 pressure from this elastic medium against gross matter, as the 

 two halves of a Magdeburg sphere were pressed together by the 

 elastic air outside when the air inside is removed. Here we 

 have a fresh explanation of hardness, as due to the motion of a 

 fluid an idea adopted in an unintelligible form by Leibnitz 



