402 AN ADDRESS ON THE RELATIONS OF 
away before my eyes, and in a few minutes was almost entirely gone. That 
redness was indubitably brought about by sympathy ; the stitches acted upon 
certain nerves, and through the nervous system the inflammatory disorder was 
produced. I imagine that all physiologists will admit that determination of 
blood might be induced through the nervous system. But it is not only this 
effect that we see from tight stitches ; we see also in time oedema, and we may 
even see death of tissue from the violence of inflammatory disturbance in the 
more immediate vicinity of the stitch, though the stitch only acts directly upon 
a microscopically small portion of the tissue. 
Counter-irritation seems to be based upon a law in physiology, which 
I may take the liberty of illustrating by some simple examples. Suppose 
a fly settles upon the skin of the face: we experience an intolerable sense of 
itching ; we rub the part with the finger, and the itching disappears—a fact 
familiar to all the world. But now I find that the same effect of removing 
the sense of itching takes place if, instead of rubbing the actual spot on which 
the fly settled, I rub in a ring round it, without touching the spot at all. What 
is the interpretation of those facts? In the first place, I suppose the sense 
of itching depends upon an abnormal action of the sensory nerves of that 
particular spot on which the fly settled. By rubbing a ring in the vicinity 
I callinto play a strong action of the sensory nerves of a neighbouring part of 
the skin which is in sympathy with that part on which the fly settled, by virtue 
of the same nervous connexion through which the skin of the chest blushed 
as the result of a tight stitch. And this new nervous action occurring leads 
to the cessation of the abnormal action which was previously going on; as if 
the attention, so to speak, of the nervous system were distracted from the 
affected part. That may seem a very homely illustration; but if the inter- 
pretation is correct, it serves the purpose none the worse on that account. 
Suppose, again, we feel a sense of irritation in the Schneiderian membrane— 
a sense of irritation which, if it goes on, will relieve itself by the violent action 
of the expiratory muscles which we term sneezing; and supposing we are 
desirous that this act should not take place—it would be inconvenient, perhaps, 
that we should sneeze—if with the hand we violently rub the tip of the nose so 
as to produce a considerable sense of uneasiness there, the sneeze is prevented. 
I do not touch the part affected with the abnormal sensation, but I call into 
play a strong action of the nerves in a part which is in sympathy with it—a part 
of the same nasal organ—and by so doing I cause the previous action to cease. 
That is another simple but instructive example of physiological counter-irritation. 
Take one more instance. I was once asked to see a young woman, pre- 
viously in perfect health, who, taking her broth—‘ kail’, as the Scotch call it— 
