A response to a professor and a speculation on the sensorium / by Bennet Dowler.

  • Bennet Dowler
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: A response to a professor and a speculation on the sensorium / by Bennet Dowler. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    6/18
    questions relative to the nervous system, anJ the revolution even now taking place in its theories, or the mere rising iqi of doubts resj)ectmg that sreat and beautiful theory of sensation and movement xohich was once sujiposed the labors of'Sir Charles Bell had settled on sure foundatimi, tend, at least, to enforce caution. Men, now, of middle age, find the whole face of physiology to have changed since they were students, and the most important parts of the change are quite recent. The Med. Chir. Rev. for April, 1849, admits that the reflex system of Dr. Hall is no longer believed in England, except by its reputed father ; or words to that cllect. It is probable that if this gentleman should renounce this system, the believers in this country would renounce it too, without a sigh, or an experiment, whereby to test its truth or false- hood. Professor LeConte, agreeably to the universal opinion, maintains the doctrine of a centralized scnsorium, though he is forced by his own conclusive experiments, to admit that the spot in which the sensorium is located cannot be in the brain, exclusively, but must extend to the spinal marrow, also, in certain animals, among which he places the alligator—a sure step—a bold step for a central sensorialist, but still not bold enough to meet the actualities of the case. In relation to the locality of the sensorium. Dr. LeConte says, that no half results,'no approximatives are sufficient; if sensation and volition are functions of the spinal cord in the lower vertebrata, experiment should give us ime- quivocal indications of it; but in his concluding remarks, he recoils from the obvious deductions which his experiments teach : Experi- ments were made on the head [of the alligator, after decapitation]—the jaws snapped at anything which touched thp teeth, tongue, or lining membrane of the mouth; while, on the other hand, tb use his own words, the motions [of the headless trunk] appear to hav^c been per- formed with a perfect knowledge of the end in view; they were par- ticularly directed to that end—were volitional—varied according as the conditions in which they were elicited, altered ;—the animal seemed to know, to intend, and to accomplish its definite object, and yet Dr. LeConte appears to repel the inevitable consequences resulting from his own experiments; for he says, It is hardly possible to conceive the co-existence of two separate and independent centres of volition and sensation in any aiiimal, because we find it impossible to under- stand how consciousness can be subdivided, thereby rejecting the very thing proved by his experiments. Dr. Le Contc does not even hint, much less admit, the possibility of a diffused sensorium. He is a centralist agreeably to the universally received doctrine of the present day ; a doctrine upon which a few hur- ried remarks will be ofiTered in the sequel, as the present occasion seems to demand. My only motive in contrasting Dr. Le Conte's views with mine, is to show the nature and extent of the experiments, and the conclusions of each, without presumptuously asserting that he is wrong, and I am right.* * I accept as satisfactory, Dr. Le Conte's explanation of the extensive leap per- formed by the separated head ofthe alligator, which I reported in the contributions,