IV Poisonous Products of Tissue Change
1. Poisonous albumin.
2. Poisons developed in food.
3. Auto-poisoning, e.g. uræmia, glycosuria, oxaluria.
4. The more important products of tissue change; such as, fatty acids, oxyacids, amido-fatty acids, amines, diamines, and ptomaines.
§ 19. I have preferred an arrangement which, as far as possible, follows the order in which a chemical expert would search for an unknown poison—hence an arrangement partly chemical and partly symptomatic. First the chief gases which figure in the mortality statistics are treated, and then follow in order other poisons.
A chemist, given a liquid to examine, would naturally test first its reaction, and, if strongly alkaline or strongly acid, would at once direct his attention to the mineral acids or to the alkalies. In other cases, he would proceed to separate volatile matters from those that were fixed, lest substances such as prussic acid, chloroform, alcohol, and phosphorus be dissipated or destroyed by his subsequent operations.
Distillation over, the alkaloids, glucosides, and their allies would next be naturally sought, since they can be extracted by alcoholic and ethereal solvents in such a manner as in no way to interfere with an after-search for metals.
The metals are last in the list, because by suitable treatment, after all organic substances are destroyed, either by actual fire or powerful chemical agencies, even the volatile metals may be recovered. The metals are arranged very nearly in the same order as that in which they would be separated from a solution—viz., according to their behaviour to hydric and ammoniac sulphides.
There are a few poisons, of course, such as the oxalates of the alkalies, which might be overlooked, unless sought for specially; but it is hoped that this is no valid objection to the arrangement suggested, which, in greater detail, is as follows:—
A — Poisonous Gases
Carbon monoxide.
Chlorine.
Hydric sulphide.
B — Acids and Alkalies
Sulphuric acid.
Hydrochloric acid.
Nitric acid.
Potash.
Soda.
Ammonia.
Neutral sodium, potassium, and ammonium salts.
In nearly all cases of death from any of the above, the analyst, from the symptoms observed during life, from the surrounding circumstances, and from the pathological appearances and evident chemical reactions of the fluids submitted, is put at once on the right track, and has no difficulty in obtaining decided results.
C — Poisonous Substances Capable of Being Separated by Distillation From Either Neutral or Acid Liquids
Hydrocarbons.
Camphor.
Alcohols.
Amyl-nitrite.
Chloroform and other anæsthetics.
Carbon disulphide.
Carbolic acid.
Nitro-benzene.
Prussic acid.
Phosphorus.
The volatile alkaloids, which may also be readily distilled by strongly alkalising the fluid, because they admit of a rather different mode of treatment, are not included in this class.
D — Alkaloids and Poisonous Vegetable Principles Separated for the Most Part by Alcoholic Solvents
Division I — Vegetable Alkaloids
Liquid volatile alkaloids, alkaloids of hemlock, nicotine, piturie, sparteine, aniline.
The opium group of alkaloids.
The strychnine or tetanic group of alkaloids—strychnine, brucine, igasurine.
The aconite group of alkaloids.
The mydriatic group of alkaloids—atropine, hyoscyamine, solanin, cytisine.
The alkaloids of the veratrines.
Physostigmine.
Pilocarpine.
Taxine.
Curarine.
Colchicin.
Muscarine and the active principles of certain fungi.
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
The digitalis group.
Other poisonous glucosides acting on the heart.
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
Santonin.
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
Poisonous amphibia.
Poison of the scorpion.
Poisonous fish.
Poisonous insects—spiders, wasps, bees, beetles, &c.
Snake poison.
Division II — Poisons Formed in Dead Animal Matters
Ptomaines.
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.