PRELIMINARY ACCOUNT OF AN INQUIRY INTO 
THE FUNCTIONS OF THE VISCERAL NERVES, 
WITH SPECIAL REFERENCE TO THE SO-CALLED 
TENEIIBIEORY SYslEM ”’ 
In A LETTER TO DR. SHARPEY, SEC. R.S. 
[Proceedings of the Royal Society of London, vol. ix, No. 32 (1858).] 
Received August 13, 1858. 
My DEAR SiR.—The fact that the irritation of visceral nerves sometimes 
causes arrest of the movements of organs supplied by them, as shown by 
Edward Weber’s experiment of stopping the action of the heart by stimulating 
the vagus, and by Pfltiger’s more recent observation that the application of 
galvanism to the splanchnic nerves produces quiescence of the small intestines, 
appears to me to have an intimate bearing upon the question how inflammation 
is developed through the medium of the nervous system at a distance from 
an irritated part; and as the nature of the inflammatory process has lately 
engaged my special attention, I have been led to make an experimental inquiry 
into this ‘inhibiting’ agency, the true interpretation of which is, as you are 
aware, still swb judice. I now propose to state the principal results at which 
I have arrived, reserving further details for a more extended communication 
which I hope soon to offer the Royal Society. 
The view which has been advocated by Pfltiger,, and I believe very 
generally accepted, viz. that there is a certain set of nerve-fibres, the so-called 
‘inhibitory system of nerves’ (Hemmungs-Nervensystem), whose sole function 
is to arrest or diminish action, seemed to me from the first a very startling 
innovation in physiology ; and you may possibly recollect my mentioning to 
you in conversation, when in London last Christmas, my suspicion that the 
phenomena in question were merely the effect of excessive action in nerves 
possessed of the functions usually attributed to them. On further reflection 
upon the subject, the consideration of the contraction produced in the arteries 
of the frog’s foot by a very mild stimulus, as compared with the relaxation of 
the vessels caused by stronger irritants acting through the same nerves, con- 
firmed my previous notions. For I could hardly doubt that the cause of the 
1 Eduard Pfliger, Ueber das Hemmungs-Nervensystem, 1857. 
