96 



SCIENCE. 



[N. S. Vol. IV. No. 82. 



periments of Claude Bernard on frogs, 

 showing that sensory nerves are not af- 

 fected by the poison, led him to the conclu- 

 sion that an animal poisoned by curare pre- 

 serves his sensibility to pain, but has lost 

 the power of giving any sign of suffering. 

 Strictly speaking, Bernard's experiments 

 only show that the drug affects the sensory 

 nerves and the spinal cord less readily than 

 the motor nerves, while they throw no light 

 on the question of the persistence of con- 

 sciousness, but the fact that they succeed 

 equally well after the removal of the cere- 

 bral lobes seems to exclude consciousness 

 from any important participation in the 

 phenomena. The arguments which have 

 sometimes been used to sustain the propo- 

 sition that curare increases the sensibility 

 to pain would prove also that small doses 

 of morphia have the same effect, whereas 

 we know that morphia in small doses di- 

 minishes and in larger doses annihilates 

 the sensibility to pain. Thus the weight of 

 physiological evidence seems to be in favor 

 of the view that curare may be to some ex- 

 tent an anaesthetic, though it is not em- 

 ployed by physiologists for that purpose. 

 Psychological evidence pointing in the 

 same direction may also be urged, for, on the 

 theory promulgated and ably defended by 

 Prof. William James, that all emotions are 

 but the conscious recognition of the reflex 

 actions produced by the exciting cause of 

 the emotions, it seems evident that so much 

 of the substratum of the feeling of pain as 

 is dependent upon the reflex contraction of 

 voluntary muscles must, in cases of curare 

 poisoning, be absolutely wanting. 



Of the possibly painful physiological ex- 

 periments which we are now considering, it 

 has been calculated by Prof. Yeo that 75 

 per cent, are rendered absolutely painless 

 by use of ansesthetics; but it must be ad- 

 mitted that the giving of an anaesthetic to 

 an animal is not the same agreeable opera- 

 tion that it is to a human being. The ani- 



mal does not understand the reason why it 

 is compelled to breathe a vapor which is 

 gradually depriving it of its consciousness, 

 and usually struggles against the adminis- 

 tration of it, thus rendering some sort of 

 forcible confinement necessary. The incon- 

 venience thus occasioned to the animal is, 

 of course, overbalanced in the case of pro- 

 longed or serious operations by the exemp- 

 tion from subsequent suffering. When, 

 however, the operation is of a trifling char- 

 acter it is doubtless more merciful to the 

 animal to dispense with the use of anses- 

 thetics. For the complete understanding 

 of this portion of the subject, it should be 

 mentioned that a large portion of the ani- 

 mals thus rendered insensible for physio- 

 logical purposes are killed after the experi- 

 ment has been performed and before the 

 effect of the anaesthetic has passed off. 

 Where the object of the research is to ob- 

 serve the subsequent effect of the operation, 

 it is, of course, necessary to allow the ani- 

 mal to recover from the anaesthetic and to 

 endure whatever pain may be connected 

 with the healing of its wounds. This has, 

 however, been reduced to insignificance by 

 the modern methods of antiseptic surgery, 

 the discovery of which was led up to by 

 physiological experiments, and the benefits 

 of which are now experienced hy the brute 

 creation as well as by the human race. 



Accepting Prof. Yeo's estimate that sev- 

 enty-five per cent, of the possibly painful 

 physiological experiments are rendered ab- 

 solutely painless by the use of ansesthetics, 

 it remains to be considered how much suf- 

 fering attends the remaining twenty-five 

 per cent, of these experiments ; and here it 

 is important, in all discusions of this sub- 

 ject, to correct a rather prevalent popular 

 notion that a wound is painful in propor- 

 tion to its depth. The fact is, however, 

 that sensibility to pain is, in a healthy 

 body, confined almost wholly to the sur- 

 face. A consideration of the function of 



