Demetrius, in the treatise which he has compiled upon the number Four, alleges certain reasons why drink should never be taken in proportions of four cyathi or sextarii. As a preventive of ophthalmia, it is a good plan to rub the parts behind the ears, and, as a cure for watery eyes, to rub the forehead. As to the presages which are derived from man himself, there is one to the effect that so long as a person is able to see himself reflected in the pupil of the patient’s eye, there need be no apprehension of a fatal termination to the malady. CHAP. 18.—REMEDIES DERIVED FROM THE URINE. The urine,[2202] too, has been the subject not only of numerous theories with authors, but of various religious observances as well, its properties being classified under several distinctive heads: thus, for instance, the urine of eunuchs, they say, is highly beneficial as a promoter of fruitfulness in females. But to turn to those remedies which we may be allowed to name without impropriety—the urine of children who have not arrived at puberty is a sovereign remedy for the poisonous secretions of the asp known as the “ptyas,”[2203] from the fact that it spits its venom into the eyes of human beings. It is good, too, for the cure of albugo, films and marks upon the eyes, white specks[2204] upon the pupils, and maladies of the eyelids. In combination with meal of fitches, it is used for the cure of burns, and, with a head of bulbed leek, it is boiled down to one half, in a new earthen vessel, for the treatment of suppurations of the ears, or the extermination of worms breeding in those organs: the vapour, too, of this decoction acts as an emmenagogue. Salpe recommends that the eyes should be fomented with it, as a means of strengthening the sight; and that it should be used as a liniment for sun scorches, in combination with white of egg, that of the ostrich being the most effectual, the application being kept on for a couple of hours.