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bility to pain, arc such different and distinct things, that 

 it is familiar to witness pain endured without abnormal 

 motion at all. On the other hand, young persons affected 

 with St. Vitus' dance, make grimaces which to those not in 

 the secret, might, from their unfamiliarity, be supposed, 

 falsely, to express pain, yet the most unseemly contor- 

 tions notoriously take place without. The epileptic, the 

 hysterical convulsions are painless ; of tetanic spasm, in- 

 deed the pain is much severer than that of inflammation ; 

 but here, in place of motion, the state is that of rigid 

 immobility. Then, as to these particular motions in some 

 creatures, concerning which so much is said, the little 

 sand-eels that you poke out of their holes in the beach, at 

 low water, wriggle exactly after the fashion of the worm on 

 the fisherman's hook; and perhaps the shape of that Avorm, 

 (like that of the eel, and the serpent,) may in great measure 

 explain the writhing which is so gratuitously supposed to 

 be expressive of its agony. In short, the " winding bout" 

 of the reptile is probably but the consequence of " its 

 linked structure long drawn out." When we have pricked 

 the insect, or wounded the worm, they may indeed move 

 violently, and be thrown into apparent agitation ; but, the 

 only certain conclusion to be deduced from that fact, is, 

 that we have stimulated the inherent irritability of a part 

 of their organisation. It is certain that no proof of the 

 worm's consciousness of the injury, or, in other words, his 

 sensibility under it, can be thus obtained; and motions 

 I will repeat it, can never prove pain, since muscular con- 

 traction, of every kind, and in every direction, is per- 

 formed entirely without consciousness.* 



* When we move our limbs indeed, we are conscious of (his 

 motion, and by that consciousness we arrive al the iruc stale of Hie 

 position of our muscles, and the ilexure of our members, but \vc 

 derive Ibis knowledge probably from Ibe proper nerves of sensation. 

 which, when we bend the arm for instance, are compressed, and it 

 is the mode and amount of pressure to which these nerves arc sub- 

 ject, that bring the brain acquainted with the slate of muscular 

 conlraclibilitv. In cases loo where muscular motion becomes iu- 



