The second stage, or stage of passive efficiency, closely resembles the third, "but differs from it in that, under favouring circumstances, the whole of the phenomena of the active efficient stage may be perfectly resumed, the heart suddenly enlarging in volume from its filling with blood, and reanimating the whole organism by the force of its renewed stroke in full tension. So far as we have yet proceeded," continues Dr. Richardson, "the whole phenomena of restoration from death are accomplished during this stage;" meaning, it would seem, that in all instances of restoration the restoration has been from the second, never from the third stage. "To those who are not accustomed to see them they are no doubt very wonderful, looking like veritable restorations from death. They surprise even medical men the first time they are witnessed by them." He gives an interesting illustration. At a meeting of the British Medical Association at Leeds, "a member of the Association was showing to a large audience the action of nitrous oxide gas, using a rabbit as the subject of his demonstration. The animal was removed from the narcotizing chamber a little too late, for it had ceased to breathe, and it was placed on the table to all appearance dead." "At this stage," he proceeds, "I went to the table, and by use of a small pair of double-acting bellows restored respiration. In about four minutes there was revival of active irritability in the abdominal muscles, and two minutes later the animal leaped again into life, as if it had merely been asleep. There was nothing remarkable in the fact; but it excited, even in so cultivated an audience as was then present, the liveliest surprise."