1889.] On the local Paralysis of Peripheral Ganglia, Sfc. 425 



extent the filaments proceeding from it to the external and internal 

 carotid arteries. Having stimulated the sympathetic in the neck, and 

 observed its normal action on the eye and on the ear, an inch and a half 

 or so of the nerve is brushed over with a 1 per cent, solution of nicotin. 

 Any excess of fluid around the nerve is removed by blotting paper, 

 and the moistening the nerve with dilute nicotin is repeated. The 

 central part of the nerve is stimulated several times at intervals of 

 about two minutes ; it produces the usual dilation of the pupil and 

 constriction of the vessels of the ear. The ganglion and the filaments 

 proceeding from it are then brushed over with 1 per cent, nicotin ; the 

 sympathetic in the neck is again stimulated ; it is found to be com- 

 pletely without effect ~; stimulation of the filaments running from 

 the ganglion to the arteries produce the normal action. Hence nicotin 

 paralyses the cells of the superior cervical ganglion. 



Besides the dilator fibres for the pupil and the vaso- constrictor 

 fibres for the ear, the cervical sympathetic contains vaso-motor fibres 

 for the head generally, and secretory fibres for the salivary glands.* 

 On these we have made a few experiments only ; but, so far, we find 

 that (in the rabbit and cat) after the application of nicotin to the 

 superior cervical ganglion stimulation of the cervical sympathetic no 

 longer causes secretion or pallor in the sub-maxillary gland, nor 

 pallor of the mouth. In fact, after nicotin has been applied to the 

 ganglion, we have been unable to detect any effect from stimulating 

 the sympathetic in the neck. 



We conclude that the dilator fibres for the pupil, the vaso-constrictor 

 fibres for the ear (probably also those for the head generally), and the 

 secretory fibres for the glands end in the cells of the superior cervical 

 ganglion. 



The paralysis of the cells is produced with remarkable ease ; in the 

 rabbit and cat a complete abolition of the effects of stimulating the 

 sympathetic in the neck results from a single " painting " of the 

 superior cervical ganglion with a small brush dipped in 1 per cent, 

 nicotin. The experiment is most easily performed in the rabbit. In 

 the cat the simplest method is to dissect away the connective tissue 

 on the mesial and dorsal side of the ganglion, to pull upwards and 

 laterally the muscles lying by the carotid, and then, without separa- 

 ting the ganglion of the trunk of the vagus from the sympathetic 

 ganglion, to moisten the exposed medio-dorsal surface of the latter 

 with dilute nicotin. Of course, by this method, some nicotin will be 

 almost certainly applied to the ganglion of the trunk of the vagus ; 

 we may mention, as showing that the nicotin affects the nerve fibres 



* According to Heidenhain (' Pfliiger's Archiv,' vol. 5, 1872, p. 316), when about 

 15 mgrms. of nicotin are injected into the vein of a dog, the sympathetic secretory 

 fibres are for a short time paralysed — presumably this is for stimulation of the 

 cervical sympathetic. 



