SIR CHARLES BELL ON THE NERVOUS SYSTEM. 
247 
cavities with the loss of power in the muscles of the jaw of that side, unequivocally 
confirm the deductions which I drew from the anatomy, that the fifth pair confers 
motion and sensation, in correspondence with its rising from the brain by two roots. In 
such a case, the trunk of the nerve, consisting of the united roots, is affected ; and 
the privation of function is complete. In the present instance, the motion alone of 
the limbs was lost, by the destruction of the anterior roots of the nerves ; whilst the 
sensibility remained, owing to the posterior roots being unaffected. 
I am unwilling to enter on so great a subject as the influence of the cerebellum, 
and of that posterior column of the spinal marrow which descends from it. Im- 
portant as these parts must be in the ceconomy, there are no facts to countenance 
the belief, that they are directly connected with the functions of motion and sen- 
sibility. Indeed the posterior column of the spinal marrow has been found softened, 
to a degree, which we must suppose inconsistent with the continuance of its func- 
tions ; and yet sensibility has been entire. But let not this fact militate against our 
conclusions. The column in the spinal marrow which gives rise to the sensitive roots, 
is posterior to that from which the motor roots arise ; but is not the posterior portion 
of the spinal marrow. Some have imagined, from finding the posterior column of 
the spinal marrow softened, in cases where sensibility was entire during the life of 
the patient, that they had found an argument unfavourable to our general conclu- 
sions. 
In consideration that the results of the experiments on the roots of the nerves of 
the spine, first made thirty years ago, have thus been confirmed by pathology, the 
Society will perhaps permit me to state how I was induced to commence these experi- 
ments. In thus adverting to my early investigations, I am only desirous of showing 
the principle which guided me in these pursuits. 
Some of the physiologists, at home and abroad, who have treated of this subject, 
have appeared to consider the facts brought out by the experiments on the spinal 
nerves, as accidental results. Misconceiving the just application of experiments to 
this inquiry, they have made it a boast, that they proceeded to their experiments 
without preparation ; and have gone so far as to represent the person who dissects 
living animals, indifferent to the results, and only curious to find something new, as 
the true philosopher ! However this may be, my experiments on the spinal marrow 
and roots of the nerves were not undertaken till after long consideration and much 
minute dissection. Many of my pupils, now risen to eminence, may remember that 
at the time alluded to, my lectures on the nervous system extended beyond what was 
customary in the courses delivered in London : not trusting to preparations, minute 
dissections were made for each lecture ; and to afford time for these, discussions on 
the physiology and pathology of the nervous system were thrown into the demon- 
stration. 
The first lecture on the distribution of the nerves, was upon presenting a display of 
\hejirst, second, third, fourth, fifth, and sixth nerves. It appeared incumbent on me 
