COMMENTARY. It is well known that the ancient authors in general represent amber as an exudation from the poplar tree, commonly found on the banks of the Po. Some of them, however, such as Lucian (De Electro), held that it is a bituminous substance. See also Theophrastus (De Lapidibus, with the annotations of Hill.) Serapion says of it, that it is formed in the sea as mushrooms are formed on land; and when the sea is troubled it casts forth large stones, and with them are cast out crusts of amber. He also gives an account, which is not very intelligible in the Latin translation, of its being swallowed up by a fish, from which, when killed, amber was procured. What is of a citrine colour, he says, is good; but what is white, like an ostrich’s egg, is bad. Upon the authority of Aben Mesuai (Mesue the elder?), he calls it a hot and dry medicine, and says it strengthens the brain, all the senses, and the heart, and is useful to old persons and men of a cold temperament. (De Simpl. 196.) Avicenna’s account of it is mostly made up from Serapion. Amber, he says, in my opinion, is an emanation from a fountain in the sea. He also repeats the account from Serapion, of its being procured from the belly of a fish which has swallowed it and dies. He must allude to the ambergris which is procured from the sperm-whale. He determines it to be hot in the second and dry in the first degree. He recommends it in exactly the same cases as Serapion. He makes mention of a species used for dyeing the hair black. (ii, 2, 62, and 364.) Rhases merely gives its medicinal character, which is the same as that quoted above from Serapion. (Cont. l. ult. 44.) But no ancient writer has given so full and correct an account of amber as Symeon Seth. He says it abounds in various places, and that there are fountains of it as of pitch, bitumen, and the like; that the best kind is of a grayish colour (grisea ambra?) and fat, which is sold in a certain city of India, called Silachetum. The ambergris or ambra-grisea, is found in a city of Arabia Felix, called Syachria. The worst kind, he says, is black, and is collected from fishes that have swallowed amber at its fountains. It has, he adds, calefacient and incisive powers, and therefore some add it to stomachic remedies. It strengthens the head and heart; and when smelled to in drinking accelerates intoxication, and still more so if added to the wine. (De Alimentis, xiii.) Psellus says, it cures dysury when appended as an amulet, removes fever, stops defluxions of the stomach, and sharpens the sight. (De Lapidibus.) Having been led along in the present instance by the ancient authorities who have given the most correct description of amber, we omitted to mention at the commencement, that Dioscorides describes the electrum under the head of populus, as being said to be the tears of poplars which have dropped into the Po, and become coagulated. He adds, it is of a fragrant smell when rubbed, and