It is also an undoubted truth, that the virtues and properties of all roots are more feebly developed, when the fruit has been allowed to ripen; and that it is the same with the seed, when incisions have been previously made in the root, for the extraction of the juice. The efficacy, too, of all plants is impaired by making habitual use of them; and these substances, if employed daily, lose equally their good or bad properties, when required to be effectual. All plants, too, have more powerful properties, when grown in soils that are cold and exposed to the north-eastern blasts, or in dry localities.