62 BIOLOGICAL PHYSICS 



and nerves, separating and supporting every unit of 

 structure, nervine and non-nervine, and keeping aseptic 

 their histological elements, while removing every material 

 obstruction to functional activity and every detached 

 particle of waste texture. While thus occupying every 

 otherwise unoccupied space without and within the whole 

 nervous system, it is capable of yielding to every special 

 requirement of every part of that system, like water in 

 a sponge, and hence on the slightest increase or decrease of 

 local, or general, pressure it escapes, or returns, along the 

 lines of least resistance, leaving the true nervine structures 

 free to functionate and maintain the continuity of sensory 

 and motor innervation ; thus, if " a determination of 

 blood to the head" takes place a corresponding determina- 

 tion of this lymph takes place to the skin, and it may be, 

 to one or other of the particular excretory agencies, and 

 so equal intra-cranio-spinal pressure is maintained. 



Its circulation may therefore be described as fitful 

 rather than regular, so as to be at all times available for 

 emergencies, however sudden or sustained ; moreover, 

 when the incidence of disease leads to an altered condition 

 physical, chemical, or bacterial, the vis medicatrix nature 

 uses every effort, by trying one and then another of the 

 exits mentioned until either success, or failure, is the result. 



It is necessary, however, to call attention here to the 

 great physiological and histological fact, that another exit 

 exists from the cerebro-spinal cavity, namely, the efferent 

 or motor nervature, through which the lymph may escape 

 into the proper texture of the muscles, and that when it 

 the lymph is septic the occurrence must be followed 

 by a greater or lesser degree of muscular disablement, 

 such, for instance, as takes place in many cases of 

 rheumatism. 



When cerebro-spinal lymph excretion keeps pace with 

 physiological requirements, and when the quality of the 

 lymph is physiologically pure, it will follow as a physio- 

 logical result that neuro-psychic health will be maintained 

 at its highest standard, and that, other physiological 

 conditions being equal, it will equally follow that a 

 condition of perfect health will be the result throughout 

 the whole organism. 



