The discrepancy here would seem insurmountable. May it not be more in appearance than in reality? One man tells me that arsenic is a poison, very liable to cause death. Another affirms that he has taken it for days in succession, and has experienced no unpleasant results. Both statements can be true, for they need not refer to the same amount. In the modern laboratory there is little danger that the animals will succumb to the effects of anaesthetic. Assuredly we may question the completeness of that insensibility which Sir Victor Horsley apparently declares may be maintained for a week.
The use of the substance known as CURARE, either alone or in connection with anaesthetics or narcotics, was naturally a subject of passing inquiry. So slight is the knowledge afforded by certain physiologists that it would almost seem that they were united in a "conspiracy of silence" regarding it; in neither of the last two editions of the "Encyclopaedia Britannica" is there more than a casual reference to the poison, and no reference to its origin. "What is it?" asked one of the Commissioners. "Is it an herb?" A brief account of the poison, in view of an ignorance so widespread, is not out of place.
Curare is the arrow-poison of certain tribes of South American Indians. It was first brought to the knowledge of Europeans by Sir Walter Raleigh on his return from a voyage to Guiana in 1595, over three centuries ago. Its actual composition, even at the present time, is unknown; it is probable that different tribes of savages have their special methods of preparing it. Some travellers claim that it consists only of a decoction of poisonous plants; others believe that with such substances are mixed the fangs of snakes, and certain species of poisonous ants, the whole compound being boiled down to the consistency of tar.
The action of the poison thus made is exceedingly rapid. Numerous experiments by different observers have demonstrated that it swiftly destroys the functions of the motor nerves of the body, leaving the sensory nerves unaffected to any extent. Claude Be'rnard, who made many experiments with curare, came to the same conclusion; it abolishes the power of motion, but has no effect upon the nerves of sensation. An American physiologist, Dr. Isaac Ott, tells us that it is able to render animals immovable "by a paralysis of motor nerves ,LEAVING SENSORY NERVES INTACT." Be'rnard asserts as a result of numerous experiments that in an animal poisoned with curare, "its intelligence, sensibility and will-power are not affected, but they lose the power of moving;" and that death, apparently so calm, "is accompanied by sufferings the most atrocious that the human imagination can conceive." Although it may seem to be a corpse without movement, and with every appearance of death, "sensibility and intelligence exist … it hears and comprehends whatever goes on, and feels whatever painful impressions we may inflict." It is only within late years, and since the employment of curare has been denounced, that anyone has suggested any doubt of these physiological conclusions.
It has been found by physiologists that if the throat of a dog be severed and the windpipe exposed and artificial respiration kept up, all the functions of life may be greatly prolonged; and if curare be used, the creature does not die, although it feels. Supposing that morphia or chloroform be administered at the same time—is the animal, notwithstanding, conscious of pain? Professor Starling admitted in his evidence that if the anaesthetic passed off, the curarized animal would be unable to move or to show any sign of suffering; there would be no possibility of a dog whining or moaning; "it could not, under curare," he frankly admits. Dr. Thane, one of the Government inspectors of laboratories, gave interesting evidence on this point, in reply to questions of one of the Commissioners.
"What is the object of giving curare when you are going to give an anaesthetic?"
"The object of giving curare is to stop all reflex movements…."
"It would stop all struggling, would it not?"
"IT WOULD STOP ALL STRUGGLING."
"That is to say, it would put an end to the usual signs of the animal not being properly under anaesthesia?"