Acts preeminently upon the system of animal life, through the motor nervous tract, affecting first the voluntary muscular system and then the sensorium ; in the former producing paralysis and tetanic convulsions, in the latter vertigo and confusion. Through the nervous irritation there is also produced a peculiar nausea and faintness, and sense of general prostration, which, in connection with the vertigo, gives a condition quite similar to that of seasickness, and either with or without the vertigo assumes a similarity to many nervous and hysterical affections, which is the most essential feature of the drug's action. Characteristic symptoms.