them in a thin canvass cloth, and suspend them within a covered vessel over the steam of hot spirit of wine, by which they will be killed and rendered friable. Lister calls them lithontriptic. Ὂνυχες, Onyches, are the covers of Indian shell-fishes. These, in a fumigation, rouse those affected with uterine suffocation and epileptics. But when drunk they disorder the belly. * * * * * COMMENTARY. Dioscorides says of the Onyx, that it is the operculum of a shell-fish, like that of the Purpura, being found in India in the lakes that produce nard; and that it acquires an aromatic smell from the shell-fishes feeding on the nard; it is gathered, he adds, when the lakes are dried up by the drought; the kind brought from the Red Sea is different, being whitish and fatty; the Babylonian is black and smaller, but both form a fragrant fumigation, resembling castor somewhat in smell. He concludes with stating, regarding their medicinal properties, that both rouse persons in hysterical convulsions, and also in epileptical, when applied in fumigations; that taken internally, they soften the belly; and that the shell-fish itself, when burnt, has the same powers as the purpura and murex. (ii, 10.) Avicenna gives a very accurate account of this article under the name of _Blacte Byzantie_; but except that he does not attribute the fragrancy of the shell to the nard it feeds on, his description is nowise dissimilar to that by Dioscorides. The medicinal virtues which he assigns to it are exactly the same. (ii, 2, 78.) Serapion gives a literal translation of the chapter of Dioscorides on the _onyx_. (De Simpl. 443.) One of Rhases’s authorities says of the _Blactiæ Byzantiæ_, that they are of a hot and dry temperament, being possessed of astringency and subtilty of parts, and that they are stomachic, hepatic, emmenagogue, and cordial. (Cont. l. ult. i, 127.) From the above account of this article, it will readily be seen that it is the cover of the _Strombus lentiginosus_. Ὄνωνις, Ononis, _Restharrow_, has a root which is desiccative in about the third degree, but the bark of it is detergent and incisive; and hence it is lithontriptic. * * * * * COMMENTARY. See Ἄνωνις. Ὄξος, Acetum, _Vinegar_, is possessed of mixed powers, namely, cold and hot, both arising from tenuity of parts; but the cold prevails over the hot. It is a desiccant of the third rank. * * * * *