The term “distilment,” says Stevens, “is calculated to support this conjecture. Surely the expression signifies that the preparation was the result of a distillation.” It is a singular fact that the essential oil of tobacco differs considerably in its physiological action from an infusion made from the leaves, the former affecting the brain, and the latter the heart.[10] [10] Paris, _Pharmacologia_, p. 294. Ellacombe states: “Before, and in the time of Shakespeare, other writers had spoken of the narcotic and poisonous effects of heben, hebenon, or hebona.” Spenser says:— “Faire Venus sonne,... Lay now thy deadly heben bow apart”. Gower and Marlowe also wrote of the juice of hebon. It may be taken for granted that all these authors allude to the same tree. Nicholson and Harrison, after a very exhaustive investigation of the subject, agree that the true reading is hebona, and that hebona is the yew. Their main arguments are based on the following three facts:— 1. That in nearly all the northern nations the name of the yew is more or less like heben. 2. That all the effects attributed by Shakespeare to the action of hebona are described by different medical writers as arising from yew poisoning. 3. That the _post-mortem_ appearances after yew poisoning and snake poisoning are similar. Later on, in the play performed before the King, Lucianus thus speaks of the poisonous medicine he uses:— “Thoughts break, hands apt, drugs fit, and time agreeing, Confederate season, else no creature seeing, Thou mixture rank, of midnight weeds collected, With Hecate’s ban thrice blasted, thrice infected, Thy natural magic and dire property On wholesome life usurp immediately”. Here allusion is made to a mixture of poisonous herbs gathered at midnight, probably hemlock among others, as mentioned in the witches’ incantation in _Macbeth_, to which we shall refer later. With regard to the gathering of herbs at night, the practice was common, it being supposed that the properties of the plant collected at night were stronger than in the daytime. That there is a certain amount of truth in this is proved by the researches of Sachs and Brown, who have found from their investigations that starch is formed in the leaves of plants during the day, and is consumed during the night, so that the old superstition of the increased activity of the midnight gathered herb was not mythical. Shakespeare’s well-known description of the poor apothecary of his time, which he introduces in _Romeo and Juliet_, presents an excellent picture of the needy practitioner in the sixteenth century:—