The document discusses the procedure for determining ash values of crude drugs. Ash values are useful for determining the quality and purity of powdered crude drugs. On incineration, crude drugs normally leave an ash consisting of carbohydrates, phosphates and silicates. The total ash reflects the preparation care, acid insoluble ash indicates contamination, and water soluble ash is an indicator of previous water soluble extraction. The procedure involves weighing the powdered drug, incinerating it to remove organic matter, and calculating the percentage of total, acid insoluble, and water soluble ash.