54 PHYSIC 



tors ideally adapted for invasion of neighbouring sound 

 textures and the propagation and perpetuation of disease. 

 Nerve influences, emanating from the systemic nervous 

 system, are thus destructive to that system itself, and 

 irresistible in their disintegrative effects on the sympathetic 

 nerve areas, which everywhere surround and support it, 

 by the intensity and continuance of their neurolytic 

 powers. A way, therefore, must be sought to prevent 

 this nerve force escape or leakage, to redirect it aright, 

 and to erect barriers to prevent the recurrence of its escape. 

 Into the therapeutic bearings of the subject, however, it is 

 yet premature to enter ; we, therefore, content ourselves 

 with reiterating that a very large number of diseases, which 

 are still looked upon as emanating from haemal quarters, 

 are none other than nervine in origin and progress, and 

 that they require to be studied anew in the light of neural 

 pathology. 



Altered pigmentation, a principal feature in the two 

 last-named of the group of diseases mentioned above, 

 viz. leucoderma and scleroderma, we elsewhere traced 

 to an origin in the central nerve structures of brain, cord, 

 and ganglia, in the nerve cells of which all physiological 

 colour phenomena of skin, hair, and cutaneous appendages 

 generally are determined and effected, where the pattern 

 is designed, and the material and energy provided by which 

 the design is peripherally carried out. Thus the nerve cells 

 elaborate the neuroplasm, which, when circulated to the 

 peripheral nerve terminals and shed into the dermic tex- 

 ture, produce, in conjunction with the modifying influences 

 of the environment, the pattern originally determined by 

 the trophic hierarchy of the united nerve commonwealth, 

 and accomplished by dynamic influences emanating from 

 the same quarter. Leucoderma seems to depend on the 

 central failure of the elements, material or dynamic, or 

 material and dynamic, of pigmentation, and represents a 

 condition of central negation or peripheral neural incapa- 

 bility of trophically dealing with the physiological neces- 

 sities of the situation. Scleroderma involves a greater 

 or lesser departure from the standard of normal pigmen- 

 tation, combined with what seems very like a pathologically 

 aggravated discharge or shedding of the neural elements 



