There would, perhaps, have been an advantage in arranging several of the individual members somewhat differently--_e.g._, a group might be made of poisons which, like pilocarpine and muscarine, are antagonistic to atropine; and another group suggests itself, the physiological action of which is the opposite of the strychnos class; solanin (although classed as a mydriatic, and put near to atropine) has much of the nature of a glucoside, and the same may be said of colchicin; so that, if the classification were made solely on chemical grounds, solanin would have followed colchicin, and thus have marked the transition from the alkaloids to the glucosides. DIVISION II.--GLUCOSIDES. 1. The digitalis group. 2. Other poisonous glucosides acting on the heart. 3. Saponin. The glucosides, when fairly pure, are easily recognised; they are destitute of nitrogen, neutral in reaction, and split up into sugar and other compounds when submitted to the action of saponifying agents, such as boiling with dilute mineral acids. DIVISION III.--CERTAIN POISONOUS ANHYDRIDES OF THE ORGANIC ACIDS. 1. Santonin. 2. Mezereon. It is probable that this class will in a few years be extended, for several other organic anitrogenous poisons exist, which, when better known, will most likely prove to be anhydrides. DIVISION IV.--VARIOUS VEGETABLE POISONOUS PRINCIPLES NOT ADMITTING OF CLASSIFICATION UNDER THE PREVIOUS THREE DIVISIONS. Ergot, picrotoxin, the poison of _Illicium religiosum_, cicutoxin, _Æthusa cynapium_, _Œnanthe crocata_, croton oil, savin oil, the toxalbumins of castor oil and _Abrus_. The above division groups together various miscellaneous toxic principles, none of which can at present be satisfactorily classified. E.--POISONS DERIVED FROM LIVING OR DEAD ANIMAL SUBSTANCES. DIVISION I.--POISONS SECRETED BY THE LIVING. 1. Poisonous amphibia. 2. Poison of the scorpion. 3. Poisonous fish. 4. Poisonous insects--spiders, wasps, bees, beetles, &c. 5. Snake poison. DIVISION II.--POISONS FORMED IN DEAD ANIMAL MATTERS. 1. Ptomaines. 2. Poisoning by putrid or changed foods--sausage poisoning. F.--THE OXALIC ACID GROUP. G.--INORGANIC POISONS. DIVISION I.--PRECIPITATED FROM A HYDROCHLORIC ACID SOLUTION BY HYDRIC SULPHIDE--PRECIPITATE, YELLOW OR ORANGE. Arsenic, antimony, cadmium. DIVISION II.--PRECIPITATED BY HYDRIC SULPHIDE IN HYDROCHLORIC ACID SOLUTION--BLACK. Lead, copper, bismuth, silver, mercury. DIVISION III.--PRECIPITATED FROM A NEUTRAL SOLUTION BY HYDRIC SULPHIDE. Zinc, nickel, cobalt. DIVISION IV.--PRECIPITATED BY AMMONIA SULPHIDE. Iron, chromium, thallium, aluminium. DIVISION V.--ALKALINE EARTHS. Barium. III.--Statistics.