Before concluding our present commentary, it may be proper to remark, as tending to show the importance of the Galenical theory of the action of medicines in the literature of medicine, that not only was it generally adopted by most of the Greek and Arabian authorities subsequent to Galen, but it prevails in the works of all our old herbalists, as, for example, Gerarde, Parkinson, Culpeper, and of the other writers on the Materia Medica, down to the days of Quincy. We may also take the present opportunity to state that in the works of the ancient authorities, we have detected a few traces of the singular doctrine of signatures, as it has been called, but that with the exception of Geber, who can scarcely be held to be a medical writer, we have found no allusion to alchemy _or_ astral influence, as having anything to do with the operation of medicines. The first ancient writer who notices alchemy, we believe, is Firmicus (iii.) Though the Arabians were much given to this superstitious conceit, it would appear from what we have mentioned that their medical authorities had kept their minds free from the contamination of it. SECT. III.—ON THE POWERS OF SIMPLES INDIVIDUALLY. COMMENTARY. The part of our task upon which we are now entering is at once so arduous and important, that we cannot but feel diffident of our abilities to execute it properly. We may venture, however, to assure the reader that we have spared no pains as far as lay in our power to unravel the intricacies with which this department of ancient science is involved, and that, with this intention, upon every article we have carefully compared the descriptions of the ancient authors, and have likewise availed ourselves of the learned labours of modern commentators on Theophrastus, Pliny, and Dioscorides. We may mention that those we have generally reposed most confidence in are Matthiolus, Dodonæus, Harduin, Stackhouse, Schneider, Sprengel, and Sibthorp. It will also be seen that we have paid a good deal of attention to the works of our English herbalists, the study of whose works we consider highly important, as reflecting much light on the ancient literature of this subject. We have further culled freely from a variety of other sources. As our limits prevent us from entering into the discussion of controverted points, we are under the necessity of merely giving the result of our own investigations in each case. Those who wish to see the commentator’s opinions more fully on these matters are referred to the Appendix to Dunbar’s ‘Greek Lexicon,’ which was written exclusively by him. Ἀβρότονον, Abrotonum, _Southernwood_, warms and dries in the third degree, being of a discutient and cutting nature, for it is possessed of a very small degree of sourness, and if rubbed with oil over the whole body, it cures periodical rigors. But it is prejudicial to the stomach; and the burnt being more desiccative than the unburnt, cures alopecia, along with some of the finer oils.