Corrosive Sublimate.[220] Verdigris. Muriate and Oxide of Tin. Sulphate of Zinc. Nitrate of Silver. Concentrated Acids. Caustic Alkalies. Cantharides. Bryony. Elaterium. Euphorbium. Colocynth. Hedge Hyssop. Ranunculi. Nitre. ─────────────────────────────────────────────────────────────────────── The _First Class_ of our arrangement comprehends such poisons as operate, through the medium of the nerves, upon the organs immediately subservient to life; in their application it is obvious that they cannot require to be introduced into the stomach; they may convey their destructive influence by an application to any part duly supplied with nerves, and whose extremities are exposed to their action. It had been long admitted that a poison might occasion death, by acting on the nerves of the stomach and intestines without being absorbed; but to the experimental labours of Mr. Brodie[222] we are principally indebted for our present correct views of the subject. The class admits of two important divisions, into one comprehending those poisons which destroy the functions of the brain, and into another, including those which direct their influence upon the heart. We shall offer a few observations upon the facts which have suggested such a division, and upon the practical advantages which may attend its adoption.