This section is from the book "Materia Medica And Therapeutics - Vegetable Kingdom", by Charles D. F. Phillips. Also available from Amazon: Materia Medica And Therapeutics: Vegetable Kingdom.
Active Ingredients. - The plant has not been subjected to very thorough chemical analysis. Enz, however, has obtained a tannin-like body, euphrastic acid (Euphrastannsaure) of the composition, C32H10O17.
Therapeutic Action. - When the curious doctrine of signatures reigned supreme in medicine, this plant enjoyed an extended reputation in various diseases of the eyes, and led to its popular appellation (in German, Augentrost). As a mild astringent in catarrhal conjunctivitis it is undoubtedly of service, and Paullus1 speaks of it as a drying remedy ("quia oculorum fluxiones sistet"). Its moderate virtues in this respect are more than equalled by its decided utility in acute nasal catarrh (cold in the head). A few drops of the tincture, taken at the beginning of the affection, and repeated every two or three hours, will often abort it. This we know by personal experience. During the past year a number of friends have, at our suggestion, used it in catarrhus aestivus, and report very distinct mitigation of their sufferings.
Preparations And Dose. - There are no officinal preparations. We have used with satisfaction the imported tincture from the fresh plant, dose m j. - v., in a wineglass of water; as a collyrium, m v. - xx. to an ounce of distilled or of rose water. As the plant is found in the White Mountains (N. H.), about Lake Superior and northward (Gray), extended trials of it could without difficulty be made.)
1 Quadripartium Botanicum, Frankfort, 1708.