[231] Dr. Carpenter tells a similar story of Admiral Codrington, who, when a midshipman, could always be awakened from the profoundest slumber if the word “signal” were uttered; whereas no other word disturbed him.
[232] Compare an interesting personal example given by Jouffroy, quoted in Sir W. Hamilton’s Lectures, I. 331.
[233] Lancet, 10th July, 1858.
[234] Marshall Hall in Philos. Trans., 1833. Lectures on the Nervous System and its Diseases, 1836. New Memoir on the Nervous System, 1843.
[235] Müller, Physiology, I. 721.
[236] It is better simply to remove the brain, than to remove the whole head, which causes a serious loss of blood. An etherized animal may be operated on with ease and accuracy. For many experiments, mere division of the spinal cord is better than decapitation. Great variations in the results must be expected, because the condition of the animal, its age and sex—whether fasting or digesting—whether the season be spring or summer—and a hundred other causes, complicate the experiment.
[237] Volkmann, quoted by Pflüger.
[238] Unzer, The Principles of Physiology (translated for the Sydenham Society), p. 235.
[239] Even so eminent an investigator as Goltz has fallen into this confusion. He introduces an experiment to prove that the brainless frog is insensible to pain by the words “when an animal, placed under circumstances which would be very painful, makes no movement, although quite capable of moving, the least we can say is that it is improbable that the animal has sensation” (Nervencentren des Frosches, p. 127). I need not discuss the proof itself, having already done so in Nature, Vol. IX. p. 84. The point to which I wish to call attention is the confusion of insensibility in general with insensibility to pain.
[240] See Duchenne, De Électrisation localisée, p. 398. Griesinger cites various examples of insane patients who have burned the flesh off their bones while manifesting a total indifference to these injuries. Maladies Mentales, p. 94. Falret says, “Nous avons vu plusieurs fois des aliénés s’inciser, s’amputer eux-mêmes diverses parties du corps sans paraître ressentir aucune souffrance.” Leçons cliniques de Médicine Mentale, 1854, I. 189. Patients incapable of feeling the contact of a hot iron with their skin have felt subjective burnings in the skin thus objectively insensible.