It was Liebig's theory that arsenic proves poisonous not by virtue, so to speak,of its own venom, but by arresting those processes of decomposition and destruction whichare always going on among the solids and fluids ol the body, as an essential agency of life. Dr. Cockle, of England, in his late pamphlet" On the Poison of the Gobra di Capello," thinks the poison of that serpent acts by promoting unduly those processes. Granting that both are right, the poison of the cobra and arsenic may be quoted as types if two different classes of poison, the septic and anti-septic