The bark of the _root_ cut into slices, and dried in small rolls or quills like cinnamon, is sometimes used in medicine in cases of obstruction of the liver. The flower-buds of the marsh marygold (_Caltha palustris_), and of nasturtiums, are frequently pickled and eaten as a substitute for capers. 171. _The WHITE POPPY_ (Papaver somniferum) _is a naturalized English plant, with smooth calyx and seed-vessels, and with leaves embracing the stem, which grows wild in neglected gardens, and some corn-fields, and to which we are indebted for two important medicines_, opium _and_ laudanum. Although the white poppy has long been naturalized in this country, it is supposed that we were originally indebted for it to some of the northern parts of Asia. Throughout nearly the whole of that quarter of the world it is cultivated with great attention, on account of the _opium_ which is obtained from it. Opium is the dried juice of the seed-vessels, and is thus procured:--After the petals have fallen off, and the seed-vessels are about half grown, the latter are wounded on one side, with an instrument having four or five teeth, the gashes being made about an inch in length. A glutinous, milky fluid exudes from the wounds: this is carefully scraped off, on the ensuing day, by a person who, in similar manner, wounds the opposite side of the head; the juice issuing from which is afterwards similarly collected. The whole is then put into earthen vessels, where it is worked by the hand, in the open sunshine, until it attains sufficient consistence to be formed into balls, cakes, or loaves; after which it is covered over with poppy or tobacco leaves, and further dried, till it is in a proper state for exportation. _Opium_ is of reddish brown colour, inclining to black; and has a strong and very peculiar smell. It is adulterated in various ways; by an extract of the plant, obtained by boiling; by a powder of the dried leaves and stalks, mixed with some kind of gum; by rice flour, and by other substances not quite so agreeable as these.