What drugs the Venetian poisoners used is uncertain. The Italians became notorious in the sixteenth and seventeenth centuries for their knowledge of poisons, partly from the deeds of Toffana and others, and partly from the works of J. Baptista Porta, who wrote a very comprehensive treatise, under the title of _Natural Magic_,[10] and managed to slide into the text, in the sections on cooking (_De Re Coquinaria_, lib. xiv.), a mass of knowledge as to the preparation of poisons. There are prescriptions that little accord with the title, unless indeed the trades of cook and poisoner were the same. He gives a method of drugging wine with belladonna root, for the purpose of making the loaded guest loathe drink; he also gives a list of solanaceous plants, and makes special mention of nux vomica, aconite, veratrum, and mezereon. Again, in the section (_De Ancupio_, lib. xv.) he gives a recipe for a very strong poison which he calls “_venenum lupinum_;” it is to be made of the powdered leaves of _Aconitum lycoctonum_, _Taxus baccata_, powdered glass, caustic lime, sulphide of arsenic, and bitter almonds, the whole to be mixed with honey, and made into pills the size of a hazel-nut. [10] J. Bapt. Porta, born 1537, died 1615. _Neapolitani Magiæ Naturalis._ Neapoli, 1589. In the section _De Medicis Experimentis_ he gives a process to poison a sleeping person: the recipe is curious, and would certainly not have the intended effect. A mixture of hemlock juice, bruised datura, stramonium, belladonna, and opium is placed in a leaden box with a perfectly fitting cover, and fermented for several days; it is then opened under the nose of the sleeper. Possibly Porta had experimented on small animals, and had found that such matters, when fermented, exhaled enough carbonic acid gas to kill them, and imagined, therefore, that the same thing would happen if applied to the human subject. However this may be, the account which Porta gives of the effects of the solanaceous plants, and the general tone of the work, amply prove that he was no theorist, but had studied practically the actions of poisons.