COMMENTARY. That it was the sub-species of sulphuret of arsenic, called realgar, namely, “the red orpiment” of Jameson, can admit of no question. In our Appendix to this section, we shall have something to say relative to the sandaracha of the Arabians. Dioscorides says it has the same general powers as arsenic (yellow orpiment), and recommends it externally in alopecia, leprosy, phthiriasis, hard boils, ulcers in the nose and mouth, other exanthemata and condylomata; and also internally in cases of empyema with mulse; in fumigations with resin in chronic cough, when its steam is inhaled into the mouth by means of a syphon. He concludes by saying of it, that in a linctus with honey it clears the voice, and along with dry pitch makes an excellent pill for asthmatics. (v, 121.) Galen, Aëtius, and Oribasius give but a very brief and general account of it. Celsus places it in his lists of cleansing and corroding substances (v, 5, 6), and often prescribes it as a septic and caustic application. Avicenna treats of the white, the yellow, and the red arsenic in the same chapter. What he says of the last, or realgar, is taken from Dioscorides. (ii, 2, 48.) Serapion also treats of the yellow and red arsenic in the same chapter, and merely gives extracts under this head from Dioscorides and Galen. See further Rhases (Cont. l. ult. i, 610); Averrhoes (Collig. v, 43); Haly Abbas (Pract. ii, 48, 503); Ebn Baithar (i, 527.) The last of these gives an interesting description of three kinds of arsenic, namely, the yellow, the red, and the white. The red of course is the article now under consideration. He says of the yellow and red, that when calcined they become white, and when melted with a certain red ore lose their disagreeable smell. The white is said to be a mortal poison. The yellow and the red he recommends in phagedænic sores of the mouth and nose and elsewhere, and as an inhalation in asthma and orthopnœa. Σάνδυξ, Sandyx, or Siricon, consists of subtile parts, and has desiccative powers, but not heating. * * * * * COMMENTARY. Galen says that when ceruse is burnt, that is to say, calcined, it becomes sandyx. (De Simpl. ix.) See also Pliny (H. N. xxxv, 23.) He calls it burnt ceruse mixed with an equal proportion of rubrica. See also Alston and Sprengel. Dioscorides treats of it under the same head as ceruse, and describes the process by which the latter is converted into sandyx. The Arabian authorities, in like manner, treat of it along with ceruse. See Serapion (c. 378); Avicenna (ii, 2, 117.) From what has been said, then, it will be readily seen that it was merely a peculiar preparation of ceruse. Σαπρότης ξύλων, Caries lignorum, _Carious Wood_, and especially that of the elm, cleanses and fills humid ulcers. * * * * *