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.