CH. IV.] MATTER AND SPIRIT. 441 



through the transformation of as much molar motion as is 

 implied in the fall of 772 pounds of matter through one foot 

 of space ; and it will lose its present form of existence as 

 fast as it is retransformed into molar motion of expan- 

 sion, or into other modes of molecular motion, according to 

 superinduced circumstances. So when food is taken into the 

 organism and assimilated with the tissues, the quantity of 

 molecular motion involved in the secretion of bile by the 

 liver, or in the raising of the arm by an act of will, or in the 

 knitting of a new plexus of associated ideas by the opening 

 of new communications between brain-cells, may equally be 

 said to have acquired its present specific forms through 

 transformation from the potential motion latent in the pre- 

 pared food. So we may say, very roughly, that there is a 

 metamorphosis of molar motion into heat and actinism; of 

 heat and actinism into the potential motion latent in the 

 nutriment ultimately derived from sun-nourished vegetable 

 tissues ; of this potential motion into undulations among the 

 molecules of nerve ; of these undulations back into molar 

 motions of the muscles which move limbs, or into mole- 

 cular motions of secreting glands, and so on, in a never- 

 ending circuit. The circuit is thus very roughly described, 

 but such is essentially its character. But now let us note 

 that throughout this wondrous circuit, from molar motion to 

 molecular nerve-motion, and back again to molar motion, 

 there is no question of Mind whatever. The metamorphosis 

 is always from one species of material motion into some 

 jther species of material motion, but never from a species 

 of material motion into an idea or a feeling. The dynamic 

 circuit is absolutely complete without taking psychical 

 manifestations into the account at alL Now obviously 

 the most that molecular physics can ever accomplish 

 will bs to point out, in more and more minute detail, the 

 characteristics of the various metamorphoses which occur 

 within the limits of this circuit. The ideal goal of physical 



