on the Reflex Fimction of the Sphial Marrow. 129 



miting; the parturition too which takes place even after death, 

 just like the firm apphcation of tlie pharynx round a finger 

 introduced into it in a beheaded young animal, shows us, of 

 what important influence, and how intimately connected V^ith 

 life, this power of the spinal marrow is, of being excited to 

 motorial discharges by local excitations of its sensitive (or 

 perceptive) nerves. In many of the stimulations belonging to 

 this class, in vomiting, &c., the sympathetic nerve may indeed 

 take some part, but it is nothing more than that of reflecting, 

 like all other sensitive nerves, the stimulation to the sensorium. 

 But that it may have this actitm may be shown by an experi- 

 ment on rabbits; for instance, by tearing the splanchnic nerve 

 in the abdomen, I have observed frequent twitchings of the 

 abdominal muscles, and have repeatedly seen the same phaeno- 

 menon in other rabbits, though the same experiments did not 

 succeed with me in dogs. * 



"3. In the cases mentioned under 2, the reflected motion is- 

 the motion following on perception, and diffiised through a 

 large series of nerves, the respiratory nerves, and it arises 

 most easily from stimulation of the mucous membranes; but 

 in greater stimulation the difflision of the reflected motions 

 may be still greater, and affect nearly all the nerves of the 

 trunk, when the irritable condition of the spinal marrow is 

 extensive. Among these cases are to be reckoned those of 

 sporadic cholera, (I do not mention Asiatic cholera because 

 of the obscurity of that disease,) in which, when severe, spasms 

 may take place even in the trunk. 



" 4. In the reflected motions which arise from violent per- 

 ceptions of the cutaneous nerves, and not those of the mucous 

 membranes, the group of respiratory motions is not brought 

 into associated action, but there more usually occur spasms of 

 the muscles of all the nerves of the trunk without spasmodic 

 respiratory motions. The highest degree of this is the epi- 

 leptic spasm from local nervous affections and the tetanus 

 traumaticus from injury of a nerve. 



"If the first demonstration of the phaenomena of reflection in 

 the first part of this manual * which appeared in the spring of 

 1833, and which I have here enlarged with reference to the 

 observations of Van Deen, be compared with Dr. Marshall 

 Hall's demonstration, a remarkable correspondence is found 

 in the ideas and instances. 



[To be continued.] 



* See note, p. 53. 



Third Series, Vol. 10. No. 59. Feb. 1837. S 



