His botany is very defective. He classifies plants in the crudest way; often only by a similarity of names. Of many his only description is that it is “well-known,” a habit which has got him into much trouble with modern investigators who have looked into his work for historical evidence verifying the records of herbs named in other works. Hyssop is an example. As stated in the section entitled “The Pharmacy of the Bible,” it has not been found possible to identify the several references to hyssop in the Bible. Dioscorides contents himself by saying that it is a well-known plant, and then gives its medicinal qualities. But that his hyssop was not the plant known to us by that name is evident from the fact that in the same chapter he describes the “Chrysocome,” and says of it that it flowers in racemes like the hyssop. He also speaks of an origanum which has leaves arranged like an umbel, similar to that of the hyssop. It is evident, therefore, that his hyssop and ours are not the same plant. The mineral medicines in use in his time are also included in the treatise of Dioscorides. He mentions argentum vivum, cinnabar, verdigris, the calces of lead and antimony, flowers of brass, rust of iron, litharge, pompholix, several earths, sal ammoniac, nitre, and other substances. Other treatises, one on poisons and the bites of venomous animals, and another on medicines easy to prepare, have been attributed to Dioscorides, but it is not generally accepted that he was the author. The best known translation of Dioscorides into Latin was made by Matthiolus of Sienna in the sixteenth century. The MS. from which Matthiolus worked is still preserved at Vienna and is believed to have been written in the sixth century. The very competent authority Kurt Sprengel, while recognising the defects in the Materia Medica of Dioscorides, credits him with the record of many valuable observations. His descriptions of myrrh, bdellium, laudanum, asafoetida, gum ammoniacum, opium, and squill are selected as particularly useful; the accounts he gives of treatments since abandoned (some of which are mentioned above, but to these Sprengel adds the application of wool fat to wounds which has been revived since he wrote), are of special interest; and the German historian further justly points out that many remedies re-discovered in modern times were referred to by Dioscorides. Among these are castor oil, though Dioscorides only alludes to the external application of this substance; male fern against tape worms; elm bark for eruptions; horehound in phthisis; and aloes for ulcers. He describes many chemical processes very intelligently, and was the first to indicate means of discovering the adulterations of drugs. GALEN.