Cancer occurs in every part of the body; for it takes place in the eyes and uterus (as we have stated when treating of those parts), and in most other parts of the body; but it is more particularly frequent in the breasts of women, because owing to their laxity, they readily admit the thick humours which occasion it. For cancers are formed by black bile overheated; and if particularly acrid, it is attended with ulceration. On this account, they are darker than phlegmons, without being attended with the same degree of heat. The veins are filled and stretched around like the feet of the animal called cancer (crab), and hence the disease has got its appellation. But some say that it is so called because it adheres to any part which it seizes upon in an obstinate manner like the crab. Owing to the thickness of the humour which occasions it, cancer is an incurable disease, for it can neither be repelled nor discussed; not yielding to purging of the whole body, resisting the milder applications, and being exasperated by the stronger ones. It may be possible, however, to prevent incipient cancers from increasing, by evacuating the melancholic humour before it becomes fixed in the part. We may evacuate, first, if nothing prohibit, by venesection, and afterwards by purging at the commencement, with the simpler purgatives, such as giving dodder of thyme to the amount of oz. ivss; in whey or honied water, and afterwards hiera, containing the black hellebore. The juice of strychnos may be applied to the ulcerated parts without exciting pain, a linen rag being folded and wetted in it, and laid on; but externally to this, we must apply soft wool, which also has been soaked in the juice, and care must be taken that they do not become dry, by frequently pouring on some of the juice. In all carcinomatous ulcers of a chronic nature, one may use the preparation from pompholyx; and those remedies which were mentioned in the Third Book for cancers in the womb may be applied with advantage. _For carcinomatous and malignant ulcers, for rugose ulcers on the fundament, and for inflammations on the pudenda, testicles, and breasts._ In a leaden mortar, and with a leaden pestle, having triturated the Lemnian earth with oxycrate and honied water or milk, so that it become black, or having triturated rose-oil, or the oil of unripe olives, or the juice of house-leek, or that of wall-pennywort, or of lettuce, or of fleawort, or of unripe grapes in like manner, anoint with them. The patient’s diet should consist principally of the juice of ptisan and the whey of milk, and from among pot herbs, of mallows, orache, blite, and gourd, of the fishes which live among rocks, and of all kinds of fowls, except those that live in marshes. _From Archigenes, for carcinomatous and malignant ulcers._ Levigate equal parts of burnt river crabs and calamine, and sprinkle or apply the ashes of crabs with cerate; or apply the seed of hedge mustard triturated with honey.