696 PHYSIOLOGY IN BELATION TO 



suppose must be acknowledged, w^ith perhaps an exception as to 

 the relative statistical frequency of neuralgia of the first division of 

 the fifth, to be only too real facts. By laying the physiology of 

 the cervical sympathetic alongside of the natural history of an 

 attack of neuralgia, we shall be enabled, I believe, to see that there 

 are stages in each corresponding with stages in the other, but that 

 it is a stage of spasm in the one, and not a stage of relaxation and 

 congestion, which corresponds with the stage of pain in the other. 

 Stimulation of the upper cervical sympathetic produces, more or 

 less immediately, contraction of the blood-vessels of the head and 

 dilatation of the pupil, and diminution of the temperature. This 

 is the first line of operation, resulting in what Brown-Sequard 

 (^ Lectures on the Physiology and Pathology of the Nervous Sys- 

 tem,' i860, p. 142) calls 'Decrease of Vital Properties.' But after 

 a while the reverse of all this takes place, and the vessels dilate. 

 Now whether this be so in consequence of exhaustion, as is ordi- 

 narily said (e.g. Funke, 'Physiologic,' vol. ii. p. 772), or not, as 

 Dr. Loven (who says in Lud wig's ^ Arbeiten Phys. Anst.,' Leipzig, 

 1 865, p. II, that the sympathetic is not so easily tired) thinks, is 

 of no consequence, or of little consequence, as the fact of the 

 sequence of events is accepted as I have stated it on all hands. 

 Indeed, similar alternations of alteration in the calibre of vessels 

 take place, as is well known, spontaneously, as the phrase goes — 

 whether rhythmically or not, still chronometrically in relation to 

 the needs of the animal and its tissues ; in the arteries of the 

 rabbit's ear (Funke, loc. cit. ii. p. 771, citing Schiff and Callenfels), 

 in the veins of the bat's wing (Wharton Jones, ^ Phil. Trans.' 1852), 

 in the arteries of the frog's web (Lister, 'Phil. Trans.' 1858, 

 P- ^53) '■> ^^d tbe occurrence of these latter alternations makes the 

 occurrence of the former more intelligible. Now, a similar alterna- 

 tion from a stage of contraction of blood-vessels, of coldness of 

 skin, of shivering, of total absence of heat, redness, swelling, or 

 tenderness, to one of increased circulation, swelling, heat, and 

 tenderness, constitutes two stages in an attack of neuralgia, homo- 

 logous with the two described as occurring in irritation of the 

 sympathetic. It is rare, I believe and Dr. Anstie teaches (' Stimu- 

 lants and Narcotics,' 1864), for pain, as opposed to tenderness, to 

 persist after congestion ; and pain in tissues differs as much from 

 tenderness as remorse in a conscience differs from tenderness in 



