It is a natural Supposition, that when a Country produces a Commodity, in a Manner peculiar to herself, the Manufacturers will embrace the most ready Means of collecting it. The first Consideration generally is, how to make the greatest Emolument with the least Labour; if the Opium, which is brought into _Europe_, were to be taken from the Head of each Poppy, by Incision, as is supposed by some Authors, the Produce would not be sufficient to supply the Markets; for as the daily Collection of Opium, from one Head, could not exceed one Grain in Weight, and many might fail even of that the Labour, Time, and Hands requisite to gather one Pound only, must necessarily make that Article, five, if not ten Times the Price it now bears. Though it is not improbable, that Opium, being a pure body, and wholly volatile, _may_ be gathered by Incision, Yet it is not natural to suppose, that the Quantity of Opium, so nicely produced can answer, in any moderate Proportion, what may be made by gathering the Heads, while green, grinding them, and expressing the Juice, which may be easily inspissated. _Vide Plin. Secund._ Lib. 20. Cap. 18. Some Authors apprehend, that common Opium is not made alone from the Head, but from the impressed Juice of the whole Plant; and indurated by the Sun's Heat, _See Mathiolus, Scaliger, &c._ But, if the Authority of _Pliny_ is not thought sufficient, _Geoffroy_ further refutes this Opinion; clearly proving, by extracting the Juice of the Leaves and Stem of the Poppy-Plant, that on the most strict Analysis, it is many Degrees inferior in Strength to the Properties of common Opium. This is also confirmed by the Examination of the Fæces, or impure Parts, remaining from the Solution of our Opium, they having no Similitude to the woody Fibres belonging to the Plant, which might pass with the Juice, by the Force of the Press, but to the light spongy Particles from the Apex or Head, with some little Grit. We have several Instances of the fæculent Parts of inspissated Vegetable Juices increasing the Violence of their Operation; such are the Aloes of the Shops, Scammony, and grosser Juice of the wild Cucumber, called Elaterium. The _Fæculæ_ of Opium, in the State wherein we receive it, will clog the more fine Parts, and prevent their ready Passage through the Pores of the Skin; and as the Time of its Duration in the Body, by such Means, is greatly increased, the Effects must necessarily remain longer, and the deleterious Quality have more Power over the human System. _Wedelius_ says, _id certissimum habemus nunquam ab Opio ulla timenda esse incommoda si bene sit depuratum_. Lib. 1. Sect. 2. Cap. 3.