reported to be an effectual preservative against the sting of all kinds of serpents. I should remark, however, that it is a different plant from the one of the same name of which mention has been made in the preceding Book,[537] having altogether another shape and appearance. There is also another marvellous property belonging to it: in spring, when the serpents begin to cast their slough, it shoots up from the ground to the height of about a couple of feet, and again, when they retire for the winter it conceals itself within the earth, nor is there a serpent to be seen so long as it remains out of sight. Even if this plant did nothing else but warn us of impending danger, and tell us when to be on our guard, it could not be looked upon otherwise than as a beneficent provision made by Nature in our behalves. (3.) It is not, however, the animals only that are endowed with certain baneful and noxious properties, but, sometimes, waters[538] even, and localities as well. Upon one occasion, in his German campaign, Germanicus Cæsar had pitched his camp beyond the river Rhenus; the only fresh water to be obtained being that of a single spring in the vicinity of the sea-shore. It was found, however, that within two years the habitual use of this water was productive of loss of the teeth and a total relaxation of the joints of the knees: the names given to these maladies, by medical men, were “stomacace”[539] and “sceloturbe.” A remedy for them was discovered, however, in the plant known as the “britannica,”[540] which is good, not only for diseases of the sinews and mouth, but for quinzy[541] also, and injuries inflicted by serpents. This plant has dark oblong leaves and a swarthy root: the name given to the flower of it is “vibones,”[542] and if it is gathered and eaten before thunder has been heard, it will ensure safety in every respect. The Frisii, a nation then on terms of friendship with us, and within whose territories the Roman army was encamped, pointed out this plant to our soldiers: the name[543] given to it, however, rather surprises me, though possibly it may have been so called because the shores of Britannia are in the vicinity, and only separated by the ocean. At all events, it was not called by this name from the fact of its growing there in any great abundance, that is quite certain, for at the time I am speaking of, Britannia was still independent.[544] CHAP. 7.—WHAT DISEASES ARE ATTENDED WITH THE GREATEST PAIN. NAMES OF PERSONS WHO HAVE DISCOVERED FAMOUS PLANTS.