471 
THE GREAT ORGANIC NERVE. 
sitions, hypotheses, opinions, are all that the works of physiolo¬ 
gists have hitherto presented upon a question the most interesting 
of all physiologyand that, “ it would be wiser and more 
conducive to the advancement of science to confess that, at the 
present, the use of the sympathetic nerve is unknown.” It is 
unknown—it has not been experimentally proved. I am inclined 
to believe that it never can be. There is such a chain of inter¬ 
communication and connexion between the branches of this 
nerve and of every other—such a continuous plexus, if I may so 
term it—that we know not where or how we shall totally destroy 
its influence on any part. Experiment may go some way, but 
after all we shall be principally left to deductions from what we 
know of other nerves, and what they effect, and what they 
have left perfectly unaccomplished. This, i feel, ^ is unsatis¬ 
factory, but, at least, it will teach us caution in drawing our con¬ 
clusions, and diffidence in the statement and defence of our 
opinions. Some opinion, however, w r e must form, or we shall 
be perfectly at sea on many an important point of physiology 
and practice. That opinion will be confirmed, or collected, or 
overthrown, by the result of future experiments. It may prove, 
as Magendie sarcastically observes, “ a jeu ft esprit ft but we 
could tell him, that, in the conducting of experiments on subjects 
like these, there are so many circumstances to be taken into con¬ 
sideration, and so many unforeseen and unobserved causes of 
error, that the conclusion from them, and a long course of them 
too, if we could divest them of their barbarity, is a more veritable 
jeu ft esprit than any opinions that are grounded on a slow and 
careful advance from what we do know, to that which w 7 e wish 
to ascertain. 
The Function of the Great Organic continued, —I have en¬ 
deavoured, how satisfactorily you must judge, to determine the 
function of the nerves derived from the lateral column of the 
spinal chord ; and the result has been, that they are organic 
nerves: and, as being uniformly lost on some muscular expan¬ 
sion, they are motor organic nerves: guiding the mechanism and 
effecting the movements of the great machine, either totally in¬ 
dependent of the will, as in the discharge of the natural function 
of the different organs; or by constraining the voluntary mus¬ 
cles to assist or repress the action of the involuntary, when our 
comfort or accommodation,” or when the ravages of disease, 
or the preservation of life, require it. Thus the heart beats and 
the lungs heave, and the peristaltic motion of the stomach and 
intestines is carried on. But is this the whole of organic life ? 
No ; it is only a part, and a very inferior one ; it is the mechani¬ 
cal part. The food w r ould in vain traverse the stomach, and be 
