Galen speaking of the Aspic in the great city of Alexandria, says, I have seen how speedily they (the aspics) occasioned death. Whenever any person is condemned to die whom they wish to end quickly and without torment, they put the viper to his breast, and suffering him there to creep a little, the man is presently killed. Pausanias speaks of particular serpents that were to be found in Arabia among the balsam trees, several of which I procured both alive and dead, when I brought the tree from Beder Hunein; but they were still the same species of serpent, only some from sex, and some from want of age, had not the horns, though in every other respect they could not be mistaken. Ibn Sina, called by Europeans Avicenna, has described this animal very exactly; he says it is frequent in Shem (that is the country about and south of Damascus) and also in Egypt; and he makes a very good observation on their manners; that they do not go or walk straight, but move by contracting themselves. But in the latter part of his description he seems not to have known the serpent he is speaking of, because he says its bite is cured in the same manner as that of the viper and Cerastes, by which it is implied, that the animal he was describing was not a Cerastes, and the Cerastes is not a viper, both which assertions are false. The general size of the Cerastes, from the extremity of its snout to the end of its tail, is from 13 to 14 inches. Its head is triangular, very flat, but higher near where it joins the neck than towards the nose. The length of its head, from the point of the nose to the joining of the neck, is 10/12ths of an inch, and the breadth 9/12ths. Between its horns is 3/12ths. The opening of its mouth, or rictus oris 8/12ths. Its horns in length 3/12ths. Its large canine teeth something more than 2/12ths and 1/2. Its neck at the joining of the head 4/12ths. The body where thickest 10/12ths. Its tail at the joining of the body 2/12ths and 1/2. The tip of the tail 1/12th. The length of the tail one inch and 3/12ths. The aperture of the eye 2/12ths, but this varies apparently according to the impression of light.