Veratria is prepared from cevadilla by treating an alcoholic extract of the seeds and capsules with water diluted with sulphuric acid, by which the alkaloid is dissolved, and the sulphate formed in solution. To this, after concentration, magnesia is added, in order to precipitate the Veratria. The precipitate, having been washed and dried, is then treated with alcohol, which dissolves the alkaloid, and yields it in an impure state on evaporation. it is afterwards purified by boiling with water, sulphuric acid, and animal charcoal, filtering, concentrating, and precipitating with ammonia.