FUNCTIONS OP THE CEREBRO -SPINAL NERVOUS SYSTEM. 553 



recorded some years since in America. 1 The subject of it, a lady, was for 

 many months in an electric state so different from that of surrounding bodies, 

 that whenever she was but slightly insulated by a carpet or other feebly 

 conducting medium, sparks passed between her person and any object she 

 approached ; when most favorably circumstanced, four sparks per minute 

 would pass from her finger to the brass ball of the stove at the distance of 

 lj inch. From the pain which accompanied the passage of the. sparks, her 

 condition was a source of much discomfort to her. The circumstances which 

 appeared most favorable to the generation of the electricity, were an atmos- 

 phere of about 80, tranquillity of mind, and social enjoyment ; whilst a low 

 temperature and depressing emotions diminished it in a corresponding de- 

 gree. The phenomenon was first noticed during the occurrence of an Aurora 

 Borealis ; and though its first appearance was sudden, its departure was 

 gradual. Various experiments were made, with a view of ascertaining if 

 the electricity was generated by the friction of articles of dress; but no 

 change in these seemed to modify its intensity. 



CHAPTEK XIII. 



OF THE FUNCTIONS OF THE CEREBRO-SPINAL NERVOUS SYSTEM. 



1. General Summary. 



444. THE Nervous System of Man, like that of all other Animals, is com- 

 posed of ganglionic ccnlre* and nerve trunks; the former (Figs. 183, 184) 

 being essentially composed of "vesicular substance," made up of cells which 



FIG. 183. 



FIG. 



FIG. 183. Microscopic Ganglion from Heart of Frog. 



FIG. 184. Bipolar Ganglionic Cells and Nerve-fibres from the Ganglion of Fifth Pair in Lamprey. 



may be spheroidal, fusiform, caudate, stellate, or of almost any variety of 

 shape; the latter consisting entirely of " nerve-fibres," which, in their most 

 completely developed state, are tubular. If the structure of an ordinary 

 nerve like the Median be examined, it will be found to consist of an invest- 

 ing membrane of connective tissue, or perineurium, in which small vessels 



1 American Journal of Medical Sciences, January, 1838. 



36 



