COMMENTARY. Dioscorides, Galen, and Aëtius give the same imperfect account of this important medicine and poison as our author gives, and supply no additional information of any importance. The Arabians were better acquainted with its properties, having ascertained that it might be taken in its metallic state with impunity. Rhases says, “I do not think that any great harm will result from drinking mercury when it is pure, unless it be pains in the stomach and intestines. It afterwards passes out in its natural state, especially if the person who swallowed it moves about. I gave a draught of it to an ape, nor did I perceive any inconvenience arise from it, except, as I have mentioned, that it appeared to be pained in its belly, for it often bit it with its mouth, and grasped it with its hands.” (Ad Mansor. viii, 42.) Haly Abbas gives a similar account. Mercury, he says, in its natural state, is not poisonous, and merely occasions some tormina in the belly; but when killed (oxydised?) it is deleterious, and is to be remedied by giving emetics of oil and dill, and afterwards oily clysters, &c. (Pract. iv, 53.) See a similar account in Avicenna (iv, 6, 1, 2.) Mercury that has been killed, or sublimed, that is to say attenuated, produces, he says, grave symptoms, such as pain of the bowels, a bloody flux, retention of urine, and so forth. He recommends, after vomiting, myrrh in wine, with honied water, &c. Serapion mentions that fumigations with mercury are very prejudicial by superinducing nervous affections and paralysis. (De Simpl. 385.) Alsaharavius is, we believe, the only ancient author who has mentioned that rubbing the body with mercury occasions swelling of the mouth, tongue, and throat, with erosion of those parts. He directs us to wash or gargle with the decoction of dill, camomile, or mint. (Pract. xxx, 3.) Pliny mentions milk as a remedy against gypsum, ceruse, sulphur, and mercury. (H. N. xxviii.) Not having access to the unpublished MSS. of the ancient ‘Scriptores Chemici,’ we cannot pretend to determine whether or not they had acquired any considerable skill in analysing and detecting poisonous substances. See an interesting account of these mss. in Fabricii ‘Bibliotheca Græca,’ xiii, p. 747. Consult also Vossius ‘De Naturâ Artium,’ v. 9; Sir William Drummond’s Papers in the ‘Classical Journal’ on the Literature of the Ancient Egyptians; and Doutens ‘Dec. de Modern.’ p. 176. The only original work on the chemistry of the ancients which we have read with any attention is the ‘Chemia’ of Geber, which contains much curious information regarding the metals, although nothing that suits our present purpose. SECT. LXIV.—ON WHITE HELLEBORE, THAPSIA, ELATERIUM, BLACK AGARIC, WILD RUE, GITH, AND THE DOWN OF THE CACTOS.