Volatile oil of nutmeg was given by inhalation to rabbits who had received urethane and were arranged for collection of respiratory tract fluid. Doses which imparted no scent of nutmeg to the inhaled air and which were estimated to correspond to systemic absorption of 10μg to 40 μg/kg body weight acted locally to produce an increase in the soluble mucin content of respiratory tract fluid. Dose-dependent increase in volume output of respiratory tract fluid varied with the season. Bronchomucotropic action began to disappear as nutmeg odor became more pungent due to higher concentrations in inhaled air. Expectorant action appeared to be due to camphene.