With respect to the secret modes in which poisons have been supposed capable of acting, mankind have ever betrayed the most extravagant credulity, of which the numerous tales upon record afford ample proof; such as that reported of Parasapis by Plutarch, from Ctesias, in his life of Artaxerxes, who, it is said, by anointing a knife on one side by poison, and therewith dividing a bird, poisoned Statira with one half, and with the other regaled herself in perfect security. We are also told of Livia who poisoned the figs on a tree which her husband was in the habit of gathering with his own hands. Tissot informs us that John, king of Castille, was poisoned by a pair of boots prepared by a Turk; Henry VI, by gloves[[119]]; Pope Clement VII, by the fumes of a taper[[120]]; and our king John, in a wassail bowl, contaminated by matter extracted from a living toad. To these few instances of credulity may be added the offer of the priest to destroy queen Elizabeth by poisoning her saddle[[121]], and the Earl of Essex, by anointing his chair.
Incredible and absurd as these opinions now appear, they continued until a late period to alarm mankind, and to perplex and baffle judicial investigations; even Lord Bacon in his charge against the Earl of Somerset for the murder of Sir Thomas Overbury, in the Tower, seemed to give credit to the story of Livia, and he seriously stated, that “Weston chased the poor prisoner with poison after poison; poisoning salts, poisoning meats, poisoning sweetmeats, poisoning medicines and vomits, until at last his body was almost come, by the use of poisons, to the state that Mithridates’s body was by the use of treacle and preservatives, that the force of poisons was blunted upon him;” Weston confessing, when he was reproached for not despatching him, that he had given enough to poison twenty men.[[122]] The power of so graduating the force of a poison as to enable it to operate at any given period seems to have been considered possible by the earlier members of the Royal Society, for we learn from Spratt’s history of that learned body, that very shortly after its institution, a series of questions were drawn up by the direction of the Fellows, for the purpose of being submitted to the Chinese and Indians, viz. “Whether the Indians can so prepare that stupifying herb, Datura, that they make it lie several days, months, years, according as they will have it, in a man’s body, without doing him any hurt, and at the end kill him without missing half an hour’s time?”
That mankind were, in a very early stage of their existence, not only acquainted with the deadly effects of certain natural substances when applied in minute quantities, but that they availed themselves of such knowledge for the accomplishment of the worst purposes, is very satisfactorily shewn by the records of sacred as well as profane authors. But such is the ambiguity of ancient writers upon this subject, and so intimately blended are all their receipts with the practices of superstition, that every research, however learned, into the exact nature of the poisons which they employed, is necessarily vague and unsatisfactory. Of this one fact, however, we may be perfectly satisfied, that they were solely derived from the animal and vegetable kingdoms, for the discovery of mineral poisons was an event of later date; owing however to the defect of botanical nomenclature, it is even doubtful whether the plants which are designated by the terms Cicuta, Aconitum, &c. in ancient authors, were identical with those we designate by the same names. (See Pharmacologia, edit. v. vol. 1, p. 66.) With respect to the poisons of Locusta, all cotemporary writers speak of the venom of the toad as the fatal ingredient of her potions, and in the Alexipharmaca of Dioscorides we find the symptoms described, which are said to be produced by it;[[123]] but what is very extraordinary, the belief of the ancients on this matter was all but universal. Pliny is express on the subject; Ætius describes two kinds of this reptile,[[124]] the latter of which, as Dr. Badham has suggested, was probably the frog, as well from the epithet, as that he ascribes deleterious powers only to the former. It is scarcely necessary to observe that this ancient belief has descended into later times; we find Sir Thomas Browne treating such an opinion as one of the vulgar errors; and we have before alluded to the legend of king John having been poisoned by a wassail bowl in which matter extracted from a living toad was said to have been infused. In still later times, we have heard of a barrel of beer poisoned by the same reptile having found its way into it. Borelli and Valisnieri maintain that it is perfectly harmless, and state that they had seen it eaten with impunity. Spielman[[125]] expresses the same opinion, “Minus recte itaque effectus venenati a bufonibus metuuntur.” Franck,[[126]] on the contrary, accuses Gmelin of too much precipitancy in rejecting the belief respecting toad-poison,[[127]] Modern naturalists recognise no poisonous species of toad; even the most formidable of the species, to appearance, that of Surinam, is said to be perfectly harmless.
If we may venture to offer a conjecture upon this subject, we are inclined to consider the origin of this opinion to have been derived from the frequency with which the toad entered into the composition of spells or charms, into philtres or love potions, and which, like the bat and the owl, most probably derived its magical character from the gloom and solitude of its habitation. Shakspeare has accordingly introduced this reptile into the witches’ enchanted cauldron, in Macbeth.
“Round about the cauldron go;
In the poison’d entrails throw.
Toad that under coldest stone
Days and nights hast thirty-one
Swelter’d venom sleeping got,
Boil thou first i’ the charmed pot!”