on Muscular Motion. 
19 
demonstrate that there are living parts which have neither the 
one nor the other. Tendons and ligaments in a natural state 
are instances of this kind. That these parts are not supplied 
with red blood is obvious to the eye of a common observer ; no 
illustration will therefore be required to substantiate that proof. 
That they are not endowed with sensibility was, I believe, first 
taught by the late Dr. William Hunter,* who published the 
following account of it.-f- 
In a case where the last joint of the ring-finger had been torn 
off, half an inch of the tendon of the flexor muscle projected 
beyond the stump ; this it was thought right to remove ; and 
to ascertain whether it was possessed of sensibility, the follow- 
ing experiment was made : a piece of cord the thickness of the 
tendon was passed round the wrist and along the side of the 
finger, so as to project even with the end of the tendon ; the 
man was then told to turn away his head, and tell which of 
the two were cut through; the tendon was divided, and the 
man declared it was the string, not having felt the smallest 
degree of pain. 
This proof is satisfactory ; but that the cornea is possessed 
of life, by no means rests upon any negative proofs ; which I 
shall now endeavour to explain. 
The cornea in its structure is made up of membranous la- 
minae. One of these appears to be a portion of the tunica 
conjunctiva, but it is either so extremely thin, or so intimately 
connected with the lamina next to it, as not to admit of more 
than a very partial separation from it; another lamina, as I 
* This doctrine was first taught by Dr. Hunter, in the year 1746. Haller 
made experiments proving the same thing in 1750. 
t Medical Observ. and Inquir. Vol. IV- page 343. 
D 2 
