Arena, _Sand_; that on the sea-shore is sufficiently desiccative. Wherefore when heated by the sun it dries up all humid bodies which have been buried in it; and when roasted it forms a dry fomentation instead of millet or salts. * * * * * COMMENTARY. _The Sand of the Sea-shore._ We have often had occasion, in the course of this work, to mention the use of heated sand as a dry fomentation. Ἀμμωνιακὸν θυμίαμα, Ammoniacum thymiama, _Ammoniac Perfume_, is a juice of intense emollient powers, so as to dissolve scirrhous tumours and tofi. * * * * * COMMENTARY. Dioscorides describes the ammoniac as being the juice of a Ferula growing near Cyrene, and mentions afterwards that an inferior kind is also obtained from a tree of the reed tribe in Lybia, near Ammon. The reed which produces the better kind is now called the _Ferula tingitana_. Whether the inferior kind be the commercial ammoniacum of the present day, which is procured from the _Dorema ammoniacum_, does not appear certain. Dr. Hill holds that the ancients were acquainted with the two kinds which we have. In the modern Greek Pharmacopœia it is questioned whether it is the product of the _Heracleum gummiferum_, or _Ferula orientalis_. The _thymiama_, or _suffimentum_, was the finest kind of ammoniac, and was so called from being used in religious rites. Dioscorides recommends ammoniac for many medicinal purposes, both internally and externally; as for loosening the bowels when taken in a draught; for asthma and other affections of the chest when given as a linctus with honey; for indurations of the spleen and liver when applied in the form of a cataplasm; and for nebulæ of the cornea. (iii, 88.) Galen gives nearly the same characters of it. Serapion quotes Dioscorides and Galen, and adds a few other particulars of not much importance from Arabian authorities, such as that it is diuretic and emmenagogue, and expels humours from the body. (c. 268.) Rhases, Avicenna, Ebn Baithar, and Haly Abbas supply no additional information of any interest under this head. Averrhoes commends it as a medicine which softens and dissolves hard tumours. (Collig. v, 42.) Ἀμόργη, Amurca, _the Lees of Oil_, is of the second order of intensely calefacient, and desiccative medicines. By these means it cures ulcers in dry bodies, but increases and exasperates those in others. * * * * * COMMENTARY. The _amurca_, as Dioscorides states, is the sediment of strained oil. Celsus mentions it often as a strong external application, in which form it is greatly commended by Dioscorides in various affections. He says it is an article in collyria and plasters. He also speaks of its being used as an injection into the rectum, the urethra, and the vagina, in diseases of these parts. Ἀμπελόπρασον,