ACTION OF INTEEKUPTED AND CONTINUOUS CURRENTS. 173 



small nerve-tiibes placed betueeu much larger tubes, and 

 appearing iu the transverse sections of: 1. the anterior column 



e / uoQ 



gx 400 





Fig. 46. — Transverse section of nerve-tubes at dififerent heights in the medulla ate and/, 

 and in a posterior root at g. 



at the cervical enlargement, at d, fig. 45, to 200 diameters ; 2. the 

 antero-lateral column of the lower portion of the medulla, at e, 

 fig. 46, to 400 ; 3. at the level of the calamus scriptorius, at 

 /, to 400 ; 4. of a posterior spinal root, at g, to 400. 



All the groups of minute nerve-tubes in the columns of the 

 spinal cord, and in the anterior and posterior roots, are far from 

 being conclusive examples; and I have selected those depicted at 

 d, e, f, and g, in support of my thesis. 



I should also remark that the minute nerve-tubes present the 

 same diameter as those of the tubes represented at a, h, and e, in 

 fig. 45, which have been drawn from different transverse sections 

 of sympathetic ganglia, photographed, at a and h to 200, and at c 

 to 400 diameters. 



Are they, in part, the origins of the great sympathetic, and do 

 they contain, besides, the dilatator nerves of the vessels and the 

 trophic nerves ? The investigations I have made induce me to 

 admit the hypothesis ; but I repeat that I have no higher pre- 

 tension than to raise the question. 



Paet the Fourth. 



the therapeutic value op galvanization by interrupted 

 currents, and by continuous currents. direct ok in- 

 DIRECT. 



§ I. — Historical {early experiments.) 



The experiments that have been made upon the important 

 question that forms the subject of this paragraph are so numerous, 



