PHYSIOLOGY. 453 



the energy of the polar influence, and upon the size and 

 susceptibility of the substance. 



2757. Every substance has its own periods of waking 

 and sleeping, of action and repose. The pulse sleeps 

 shorter than the breathing ; this again shorter than being 

 hungry ; this again for a briefer time than the sexual 

 function. 



2758. There are organs, or systems, which are nearly I 

 always in a state of slumber, e. g. the osseous system, ) 

 because in it the polarity is extinguished. It is only in / 

 states of inflammation that it wakes up. Others scarcely 

 ever slumber, e. g. the cellular system, because in it J 

 indeed no pole is yet fixed, and in the alternation of poles | 

 its life consists. 



2759. There is a similar change of poles in a nervous 

 system, and it indeed halts or stops for a middling time. 

 Through the persistent influence of the external world, 

 the nerves of the senses are thrown into such a state of 

 tension with the brain, that blood cannot flow thither in 

 sufficient quantity, in order to maintain the two cerebral 

 substances in mutual antagonism. Brain and nerves 

 become therefore indifferent ; muscles and sensorial organs 

 lose their polarizability, and their intercourse ceases with 

 the nerves as well as the world. The brain, and every- 

 thing else, has now been discharged, and a deep sleep 

 without dreams, an animal death, ensues. 



2760. It has been arbitrarily asserted, that no sleep 

 is possible without dreams, but for this statement 

 there are no existing grounds. Whence should the 

 dream come if there is no tension in the brain, or if it 

 has previously undergone sufficient self-exhaustion ? 



Periodicity. 



2761. The sleep of the nerves ranges parallel with that 

 of the planet. It might be said that such was the case 

 from habit or custom, but it is, properly speaking, depen- 

 dent upon a parallel process of organizing that occurs at 

 the origination of the animal. The matter stands thus : 

 the germ originates in the morning ; until evening 

 stimuli act upon and polarize it : in the evening they 



