430 Local Paralysis of the Peripheral Ganglia, Sfc. [Nov. 21, 



with essentially similar results : that is, we have obtained an abolition 

 of the effect of some one or more of the classes of nerve fibres running 

 to them. We think then there is fair ground to conclude that by 

 stimulating the nerve fibres running to and those from any peripheral 

 ganglion, before and after the application of dilute nicotin to it, the class 

 of nerve fibres which end in the nerve cells of the ganglion can be dis- 

 tinguished from those which run through the ganglion without being 

 connected with nerve cells. 



There are various other questions suggested by the action of nicotin 

 which we hope to deal with later. — Does the paralysis of the ganglion 

 on the posterior root prevent the passage of a stimulus to the central 

 nervous system ? Are all afferent fibres connected with nerve cells in 

 the posterior root, or do some run through the ganglion or end else- 

 where ? Can centres be isolated, or the connexions of tracts followed 

 in the brain and spinal cord ? Does any poison when locally applied 

 to ganglia affect unequally the cells in which the different classes of 

 fibres end ? 



We append an account of an experiment upon the splanchnic to 

 illustrate the method employed. 



Rabbit. — 5 mgrms. morphia hydrochlorate injected subcutaneously. Chloro- 

 form. Cannula in carotid artery for kymographic tracing. Left splanchnic nerve 

 dissected out for \\ inch, ligatured, and cut. Peristalsis good. Secondary coil at 

 7 cm. ; this gives a current fairly strong to tip of tongue. Originally, and a3 a rule 

 after each application of nicotin sulph. to the nerve or ganglia, the splanchnic was 

 stimulated three times at intervals of a minute : since the effect of each of the three 

 stimulations was the same, we mention below one only. 



1.18 P.M. Stim. splanchnic for 30 sec. Blood pressure rose rapidly after 2 sec. 



stim., in 4 sec. rising from 70 to 90 mm. Hg, where it remained for 

 rest of stim., sinking gradually afterwards and regaining previous 

 level in \\ min. Peristalsis of intestines inhibited. 

 1.21 „ Splanchnic painted nearly up to the solar plexus with nicotin sulph. 



1 per cent. The nicotin was freely applied several times, a small 

 piece of sponge being placed under the nerve close to the solar 

 plexus to prevent the alkaloid from reaching the ganglia. 

 1.26 „ Stim. splanchnic for 15 sec. Blood pressure rose in same manner 



from 62 to 80 mm. Hg. Peristalsis of intestines inhibited. 

 1.30 „ Cceliac ganglion painted with nicotin sulph. with a small brush, a 



portion of superior mesenteric ganglion also being touched. 

 1.33 „ Stim. splanchnic for 15 sec. Blood pressure rose in same manner 

 from 72 to 80 mm. Hg. Peristalsis of intestines inhibited, but 

 apparently less readily. 

 1.35 „ Nicotin sulph. applied to whole region of solar plexus, no excess of 

 fluid being used. 



1.40 „ Stim. splanchnic for 45 sec. Blood pressure remained at same level, 



68 mm. Hg. Peristalsis of intestines not inhibited. 

 2.5^ „ Stim. splanchnic for 15 sec. Blood pressure rose in same manner as 



at first, rapidly from 58 to 79, and subsequently to 86 mm. Hg. 



Peristalsis of intestines inhibited. Thus, in half an hour the 



paralysis of the ganglia had disappeared. 



