Professor Curtis tells us that "herbs, during their growth, preserve their medicinal properties, commencing at the root, and continuing upward, through the stem and leaves, to the flowers and seeds, until fully grown. When the root begins to die, the properties ascend from it towards the seed, where, at last, they are the strongest. Even the virtues of the leaves, after they get their full growth, often go into the seed, which will not be so well developed if the leaves are plucked off early; as corn fills and ripens best when the leaves are left on the stalks till they die. In the annual and biennial plants, the root is worthless after the seed is ripe, and the stem also is of very little value; what virtue there is residing in the bark and leaves also lose their properties as fast as they lose their freshness. All leaves and stems that have lost their color, or become shrivelled, while the roots are in the earth, have lost much of their medicinal power, and should be rejected from medicine." Seeds and fruit should be gathered when ripe or fully matured. Flowers should be gathered just at the time they come into bloom. Leaves should be gathered when they have arrived at their full growth, are green, and full of the juices of the plant. Barks should be gathered as early in the spring as they will peel. Roots should be gathered in the fall, after they have perfectly matured, or early in the spring, before they commence germinating and growing. POTATO. Boiled potatoes, mixed up with steamed cornstalks, shorts, &c., make an excellent compound for fattening cattle; yet, at the present time, they are too expensive for general use. We hope, however, that ere long our farmers will take hold of this subject in good earnest,--we allude to the causes of potato rot,--and restore this valuable article of food to its original worth. A few remarks on this subject seem to be called for. _Remarks on the Potato Rot._