124 DR seller's memoir OF THE 



urine from anxiety of mind ; to these may be added, discharge of tears from acrid 

 substances, as mustard in the mouth and throat, the same from acrids affectins: 

 the nose, the copious secretion of saliva from the smell or sight of grateful food. 

 Of sympathetic sensations, the examples are, uneasy sensation affecting the teeth 

 from grating sounds, as the noise of a file, pain in the forehead from a draught of 

 cold water, pain of the head from irritation of the stomach, dimness of the eyes 

 from disordered stomach, pain at the top of the shoulder from inflammation of 

 the liver, headache from tight shoes. 



It will appear from the case referred to above, in which tickling the fauces is 

 regarded as the cause of vomiting, that Whytt's account of sympathetic acts 

 exactly coincides with the view he takes of involuntary motions in his work on 

 that subject. Nor is it to be doubted that that view is substantially correct, — 

 namel3% that the peripheral extremity of an afferent nerve being affected by an 

 impression, there results a corresponding condition of the nervous centre, whence, 

 in accordance with the constitution of the living frame, a motor influence is 

 determined, through efferent nervous filaments, to particular organs which are 

 thrown into movement. In short, that sympathetic acts are reflex acts, deter- 

 mined by the nervous centre, on the occurrence of an external impression, — 

 external, that is, to the nervous system. All that is here stated is the general 

 principle ; and perhaps it is even now premature to attempt to refer all known 

 sympathies of the nature of vegetative acts to their proper seat, respectively, in 

 the nervous centre. At all events, there is no ground to claim for Whytt any- 

 thing more than the general principle now stated, since he makes no attempt to 

 determine the separate endowments of different parts of the encephalon and 

 spinal marrow. The improvement that may be expected on this point will be in 

 proportion as the knowledge increases of the several separate offices assigned to 

 different parts of the nervous system, whether as relates to the central organs or 

 the nervous fibrils. In the mean time, the doubts which exist as to the reality 

 of such orders of nerves as the excito-motory of Marshall Hall, and the vaso- 

 motor of Brown-Sequard, tend ver}^ much to retard progress. The sympathetic 

 nerve and its ganglia are still a problem ; nor should it be too securely assumed 

 that some sympathies belonging to the order of sympathetic acts may not be the 

 result of reflex acts of its ganglia. But this time only can determine. There 

 are innumerable morbid acts, the result of irritations of sensible surfaces, which 

 have never yet been sufficiently inquired into. The tendency, however, at present, 

 among physiologists, seems to be, to deny all source of actual movement to the 

 sympathetic, and to regard its influence as being rather over chemico- vital than 

 over motive acts. Still, whatever may be the final determination, the rule of 

 sympathetic acts, within Whytt's expression, will be, that the}'- are determined 

 by impressions acting through nervous centres. 



One of the most remarkable morbid sympathies is the occurrence of cramps of 



