COMMENTARY. It would seem to be the _Paliurus australis_, Gaertn. Dioscorides ascribes to it nearly the same medicinal properties as our author. Thus, he says, it is expectorant, lithontriptic, and alexipharmic, its leaves and root being astringent, so as to stop looseness of the bowels, and that it is diuretic and discutient externally. (i, 121.) Galen and Aëtius treat of it in nearly the same terms as our author. We have not been able to detect it in the Mat. Med. of the Arabians. Πάνακες, Panaces, _All-heal_; it is from that species called Heraclium, from which the substance named opoponax is produced, being heating in the third degree, desiccative in the second, emollient and discutient. The bark of the root being weaker than the juice, is somewhat detergent and incarnative, but the fruit of it is emmenagogue. The species of Panaces which are called Asclepium and Chironium, are more heating than the former, and hence their leaves and fruit are used for ill-conditioned ulcers and phymata. * * * * * COMMENTARY. Dioscorides decides that the Heraclium is the tree which produces the famous _opoponax_. It has now got the scientific name of _Opoponax Chironium_, Koch. See Pereira (Mat. Med. 1040), and Lindley (Veg. King. 776.) Dioscorides gives a most excellent account of the process by which the opoponax is collected, and describes the marks by which that which is genuine may be recognized. He ascribes to it calefacient, attenuant, and emollient powers, and recommends it in a great variety of cases, such as periodical fevers, rigors, convulsions, bruises, pains of the sides, tormina, strangury, scabies vesicæ; as an emmenagogue, and a medicine which destroys the fœtus; as a liniment in sciatica; a good application to the holes of carious teeth; as forming a good plaster to bites of mad dogs; as an incarnant when applied to ulcers connected with exposure of the bone; and as being alexipharmic, and remedial in hysterical convulsions, and in many other cases. (iii, 48.) Galen also gives an interesting account of opoponax, which he represents as being hot in the third degree, and drying in the second. He recommends it particularly in ill-conditioned ulcers complicated with exposure of the bone. He says the fruit of the tree is emmenagogue. Aëtius treats of it in similar terms. The Arabians treat of this article at considerable length, as usual following in the footsteps of Dioscorides. See Avicenna (ii, 2, 521); Rhases (Cont. l. ult. i, 521); Serapion (De Simpl. 252); Averrhoes (Collig. v, 42.) They recommend it in hardness of the spleen, in pleuritic pains, and chronic coughs. They say it softens hardness of the uterus, and is useful in stillicidium urinæ. Both when taken by the mouth and in a suppository, they say it occasions abortion. Avicenna says that galbanum is used as a succedaneum for it, and that gum ammoniac is nearly allied to it.