The vegetable poisons known to the ancients have mostly been named. But cherry laurel, elaterium, certain fungi, and smilax, probably our mezereon, should be added. The mineral poisons in more or less use were arsenic, in the form of orpiment and realgar, cinnabar, and metallic mercury, which was reputed to be poisonous. Nicandor alludes to litharge, ceruse, and gypsum. By the last he may have meant quicklime. Berthelot translated from Olympiodorus (sixth century) the description of a process for making white arsenic from the sulphide. The product was called “alum, white and compact.” The animal kingdom furnished the Romans with at least one famous poison which they extracted from the _Lepidus marinus_ (in the Linnean system, _Aplysia depilans_) which they knew as the sea-horse. According to Philostratus it was by this poison that Domitian removed Titus. POISONINGS IN THE MIDDLE AGES. The belief in the skill of the compounders of philtres and mysterious charms grew rather than diminished in the Middle Ages and as alchemy developed. In Sir Walter Scott’s “Talisman,” the tale of the Crusades, the western physician says, “The oily Saracens are curious in the art of poisons, and can so temper them that they shall be weeks in acting upon the party, during which time the perpetrator has leisure to escape. They can impregnate cloth and leather, nay, even paper and parchment, with the most vile and subtle venoms.” Official records of the trial of a minstrel named Wondreton in Paris, in 1384, give a copy of instructions alleged to have been given to the accused by Charles the Bad, King of Navarre, who had employed this Wondreton to poison the then King of France, Charles VI, his brother, two uncles, and several dukes. The scheme was extraordinarily crude, although Charles the Bad was reputed to be an adept in alchemy. The minstrel was to buy “arsenic sublimat” from the hotels of the apothecaries in Pampeluna, Bordeaux, Bayonne, and other towns through which he would pass. He was to powder this, and get into the kitchens of the eminent persons who were to be his victims, and then, when he could do it with safety, he was to sprinkle some of the powder in the soups and meats served to the masters. Wondreton was arrested before he had done any mischief, and was executed. King John of England is alleged to have caused Maud Fitzwalter to be killed in the Tower by a poisoned egg because she would not yield to his illicit passion.