The might of Nature, too, is equally conspicuous in the animals which live upon dry land as well;[81] the beaver, for instance, more generally known as “castor,” and the testes[82] of which are called in medicine “castorea.” Sextius, a most careful enquirer into the nature and history of medicinal substances, assures us that it is not the truth that this animal, when on the point of being taken, bites off its testes: he informs us, also, that these substances are small, tightly knit, and attached to the back-bone, and that it is impossible to remove them without taking the animal’s life. We learn from him that there is a mode of adulterating them by substituting the kidneys of the beaver, which are of considerable size, whereas the genuine testes are found to be extremely diminutive: in addition to which, he says that they must not be taken to be bladders, as they are two in number, a provision not to be found in any animal. Within these pouches,[83] he says, there is a liquid found, which is preserved by being put in salt; the genuine castoreum being easily known from the false, by the fact of its being contained in two pouches, attached by a single ligament. The genuine article, he says, is sometimes fraudulently sophisticated by the admixture of gum and blood, or else hammoniacum:[84] as the pouches, in fact, ought to be of the same colour as this last, covered with thin coats full of a liquid of the consistency of honey mixed with wax, possessed of a fetid smell, of a bitter, acrid taste, and friable to the touch. The most efficacious castoreum is that which comes from Pontus and Galatia, the next best being the produce of Africa. When inhaled, it acts as a sternutatory. Mixed with oil of roses and peucedanum,[85] and applied to the head, it is productive of narcotic effects—a result which is equally produced by taking it in water; for which reason it is employed in the treatment of phrenitis. Used as a fumigation, it acts as an excitant upon patients suffering from lethargy: and similarly employed, or used in the form of a suppository, it dispels hysterical[86] suffocations. It acts also as an emmenagogue and as an expellent of the afterbirth, being taken by the patient, in doses of two drachmæ, with pennyroyal,[87] in water. It is employed also for the cure of vertigo, opisthotony, fits of trembling, spasms, affections of the sinews, sciatica, stomachic complaints, and paralysis, the patient either being rubbed with it all over, or else taking it as an electuary, bruised and incorporated with seed of vitex,[88] vinegar, and oil of roses, to the consistency of honey. In the last form, too, it is taken for the cure of epilepsy, and in a potion, for the purpose of dispelling flatulency and gripings in the bowels, and for counteracting the effects of poison.