The seed of the ferula has been by some persons called “thapsia;”[986] deceived, no doubt, by what is really the fact, that the thapsia is a ferula, but of a peculiar kind, with leaves like those of fennel, and a hollow stalk not exceeding a walking-stick in length; the seed is like that of the ferula, and the root of the plant is white. When an incision is made in the thapsia, a milky juice oozes from it, and, when pounded, it produces a kind of juice; the bark even is never thrown[987] away. All these parts of the shrub are poisonous, and, indeed, it is productive of injurious effects to those engaged in digging it up; for if the slightest wind should happen to be blowing towards them from the shrub, the body begins to swell, and erysipelas attacks the face: it is for this reason that, before beginning work, they anoint the face all over with a solution of wax. Still, however, the medical men say that, mixed with other ingredients, it is of considerable use in the treatment of some diseases. It is employed also for the cure of scald-head, and for the removal of black and blue spots upon the skin, as if, indeed, we were really at a loss for remedies in such cases, without having recourse to things of so deadly a nature. These plants, however, act their part in serving as a pretext for the introduction of noxious agents; and so great is the effrontery now displayed, that people would absolutely persuade one that poisons are a requisite adjunct to the practice of the medical art. The thapsia of Africa[988] is the most powerful of all. Some persons make an incision in the stalk at harvest-time, and bore holes in the root, too, to let the juice flow; after it has become quite dry, they take it away. Others, again, pound the leaves, stalk, and root in a mortar, and after drying the juice in the sun, divide it into lozenges.[989] Nero Cæsar, at the beginning of his reign, conferred considerable celebrity on this plant. In his nocturnal skirmishes[990] it so happened that he received several contusions on the face, upon which he anointed it with a mixture composed of thapsia, frankincense, and wax, and so contrived the next day effectually to give the lie to all rumours, by appearing with a whole skin.[991] It is a well-known fact, that fire[992] is kept alight remarkably well in the hollow stalk of the ferula, and that for this purpose those of Egypt are the best. CHAP. 44. (23.)—THE CAPPARIS OR CYNOSBATON, OTHERWISE OPHIOSTAPHYLE.