COMMENTARY. Our author’s account of the medicinal properties of _Rennet_ is taken from Dioscorides and Galen. Indeed he has copied from the latter almost word for word. The Arabians treat of the rennets very fully and with much judgment. See in particular Rhases (Cont. l. ult. i, 221); Avicenna (ii, 2, 115); Serapion (De Simpl. 444); Ebn Baithar (ii, 604.) They follow Dioscorides very closely, among other things recommending rennet to be applied on a pessary for promoting the menstrual discharge, and for the hysterical convulsion. All rennets, they say, are alexipharmic, and especially those of the kid, of the antelope, and of the camel. As stated by us in the Fifth Book, the ancients administered rennet in cases of poisoning with curdled milk. It appears remarkable that an article unquestionably capable of being applied to so many medicinal purposes as rennet, should have been entirely excluded from our modern Dispensatories. Ῥακὸς, Panniculus, _Rags_; when those from wool are burnt they have similar powers to burnt wool. Linen, when burning, sends forth a subtile smoke, so as to prove deobstruent in catarrhs, and agree with risings of the womb. When burnt, its powers are nearly the same as those of wool. * * * * * COMMENTARY. These things are so well known as not to require further illustration. Ῥάμνος, Rhamnus, _Buckthorn_, is desiccative in the second degree, but cooling in the first. Hence it cures herpes and erysipelas when not very hot. Its tender leaves are to be used. * * * * * COMMENTARY. This appears to be the first species of Dioscorides, which we may decide to be the _Lycium Europæum_. The second is the _Lycium Afrum_. The third is not well ascertained, but probably is a species of _paliurus_. See Parkinson (Theatre of Plants, 1006), and Sprengel (Ad Dioscor. i, 119.) Dioscorides recommends the leaves of all the three kinds for herpes and erysipelas, and also mentions that the twigs of them were placed in doors and windows to avert sorcery. (i, 119.) Galen and the other Greek authorities treat of this article in nearly the same terms as our author. Pliny recommends it as a cooling and refrigerant application. (H. N. xxiv, 76.) The Arabians borrow their account of it entirely from Dioscorides and Galen. See in particular Serapion (De Simpl. 236); Rhases (Cont. l. ult. i, 591); Avicenna (ii, 2, 345); Ebn Baithar (ii, 223.) Ῥάφανος, Rhaphanus, _Radish_, is heating in the third degree, and desiccative in the second. The wild is more powerful. The seeds of both are stronger, and therefore they discuss hypopion and other lividities. * * * * *