COMMENTARY. Dierbach states that three species of the oak with edible roots grow in Greece, the _Quercus Æsculus_, the _Q. Ilex_, and the _Q. Ballote_. He adds, that the first species is generally meant by δρῦς in the Hippocratic writings. Eustathius remarks that the φηγὸς of Homer was a species of oak. (Ad Iliad. v, 691.) In fact, it was the _Quercus æschylus_, or rather comprehend it and the _Q. Robur_. See Parkinson (1389.) After all the illustration which the subject has received from the old herbalists, and more recent commentators on Dioscorides and Theophrastus, it must be admitted that there is still considerable difficulty in determining the various species of oak described by the ancients. Our author borrows his account of the medicinal powers of the oak from Dioscorides, whom all the other authorities also follow. The quercus occurs in the Mat. Med. of Hippocrates, and in those of all the Arabians. We need scarcely add that the _Quercus Robur_ still maintains a place in our Dispensatory. Ἔβενος, Ebenus, _Ebeny_; the wood is calefacient, detergent, and consists of subtile particles. Hence it is believed to remove films which obstruct the pupil, and is an ingredient for other ophthalmic remedies. * * * * * COMMENTARY. The Latin poet Virgil, who applies the term India both to the region of the East, which has always held that name, and to Abyssinia (Georg. iv, 293), says, that India is the only country that produces ebeny. (Georg. ii, 116.) This account of it will still be admitted to be pretty correct. Dr. Royle mentions that “_Diospyros Ebenus_ yields the best kinds in the Mauritius, perhaps also in Madagascar; but _D. ebenaster_ and _D. melanoxylon_, the ebeny trees of the Coromandel coast, yield it in the peninsula, of very good quality, as other species do in other parts of India.” (Hindoo Med. 89.) See Ainslie (Mat. Ind. ii, 48.) In medicine it was principally used in collyria for psorophthalmia and xerophthalmia as recommended by Dioscorides (i, 129), and in old ulcers and watery pustules as recommended by Aëtius (i) and Galen. (De Simpl. vi.) See also Celsus (v, 12.) The Arabians, who must have been still more familiar with it than the Greeks, say of it, in addition, that it is lithontriptic. Rhases (Contin. l. ult. 258), Avicenna (ii, 2, 226), and Serapion (c. 152.) It is still imported to this country, but has long ceased to occupy a place in our Dispensatory. Ἐγκέφαλον,