Sprengel makes the dipsas to be the _coluber prester_, and the hæmorrhus the _C. cerastes_. That they were both vipers is quite obvious from the ancient descriptions of them, and more especially from the account of them given by Galen. (l. c.) SECT. XVI.—ON THE HYDRUS, OR WATER SERPENT. When a person has been bitten by a water serpent, the wound becomes broad, large, and pale, and a black, copious, and fetid discharge, as from a spreading ulcer, takes place, and the cure of the mischief is accomplished only after a length of time, and with difficulty. Wherefore powdered marjoram mixed with water is to be applied to their bites, or oak ashes mixed with oil, or barley-flour with melted honey is given to drink, and birthwort to the amount of two drachms in diluted wine, or two cyathi of oxycrate; and afterwards the juice of horehound, or its decoction with wine, or wild cresses, or the fruit of asphodel, or the flour or the seed of hog’s fennel, with wine. A fresh honeycomb may also be eaten with vinegar. * * * * * COMMENTARY. This section is taken almost word for word from Dioscorides. The chersydros, says Nicander, is like the asp, and its bite is followed by malignant symptoms. The skin about the wound becomes parched and putrid, along with heat and pains all over the body. Isidorus says of it: “Hydros aquatilis serpens a quo icti obturgescunt.” (Orig. xii, 4.) See also Pliny. (H. N. xxix, 22.) Haly Abbas says, it occasions lividity of the part, from which a black fetid discharge takes place. (Theor. viii, 21.) Bochart makes this to have been the serpent which so annoyed the children of Israel in the wilderness. (Hier. ii, 421.) According to Sprengel, it is the _coluber natrix_. (Notæ in Dioscor.) Gesner and Dr. Milligan make it to have been the _coluber lutrix vel chersea_, L. It is now generally held not to be venomous. We have alluded in our commentary on the fourteenth section to the confusion of the hydrus with the dryinus. Schneider has a learned annotation on this subject in his ‘Curæ posteriores’ to Nicander’s Theriacs, (l. 432.) SECT. XVII.—ON THE CENCHRINUS. When a person is bitten by the cenchrinus, the bite is like that of the echidna, mortification supervenes, and the flesh melts away, having been previously swelled as in dropsy, and he becomes lethargic and comatose. Erasistratus says that the liver, bladder, and colon are affected; for upon dissection these parts were found corrupted. Wherefore they are remedied by a cataplasm composed of the fruit of lettuce with linseed, and by pounded savory, and by wild rue, and by wild thyme triturated with asphodel; and two drachms of the root of centaury should be immediately given in a draught with three cyathi of nine, or the root of birthwort in like manner, and so also cresses and gentian. * * * * *