Note 991 — APPENDIX.

J. Kossa, considering that potassium permanganate ought, theoretically, to act as a chemical antidote to potassium cyanide, by checking the paralysis of the respiratory centres, has performed some experiments. Rabbits were shown to be fatally affected in a few minutes by 0·01 grm. of the poison, but if, at the time of administration, 0·5 grm. of permanganate dissolved in 50 c.c. of water was also introduced into the stomach, doses of cyanide up to 0·1 grm. failed to cause death. Larger quantities (0·2 grm.) proved fatal under similar conditions, but the action of the poison was much delayed. Successful experiments were also performed with aqueous solutions of hydrocyanic acid containing 0·1 per cent. It is suggested, therefore, that, in cases of cyanide poisoning, 1⁄2 to 1⁄3 litre of a 3 to 5 per cent. solution of permanganate should be administered immediately (Vratch, through Nouv. rem., ix. 567).