I conceive Tobacco to be a Plant abounding with Nitro-Sulphurious Particles; for the Planters try the goodness of their Seed, by casting a little thereof into the Fire; if it be good, it will sparkle after the manner of Gun-powder: so will the Stalks of Tobacco-leaves, and perhaps has something analogous to the Narcotick Sulphur of _Venus_, which the Chymists so industriously labour after. The World knows little of the efficacy of its Oyl, which has wonderful Effects in the curing of old inveterate Sores, and Scrophulous Swellings, and some, otherwise applied and qualified. The goodness of Tobacco I look on primarily consists in the volatility of its Nitre: And hence the sandy Grounds that are most impregnated therewith, and whose Nitrous Salt is most Volatile, for such Grounds are quickliest spent, yield Tobacco's that have the richest Scent, and that shortly becomes a pleasant Smoak; whereas, in Tobacco that grows on stiff Ground, the Salts seem more fix'd, and lock'd up in the Oyl, so that whilst new, 'tis very heady and strong, and requires some time for its Salts to free themselves, and become Volatile; which it manifests, by its having an Urinous Smell. The same Reason satisfies, why Tobacco that grows on low Lands as far as the Salts, tho' the Plant be never overflowed with Salt Water, yet the Ground that feeds the Plant being impregnated with Salt Water, that Tobacco Smoaks not pleasantly, and will scarcely keep Fire, but do all that a Man can, will oft go out, and gives much trouble in frequent lighting the Pipe, 'till after it has been kept some considerable time: Which may be assign'd to the fixeder Saline Particles of the Marine Salt in these Plants, which require more time e'er they be render'd Volatile. Here it might be worthy an Enquiry into the Nature of Filtration of Plants, since we may hence gather, Particles of the Marine Salt are carried along with the _Succus Nutritius_ of the Plant; concerning which, if it were not too much to deviate from the Matter in hand, I should offer some Reflections of my own, which the Learned Society might perhaps improve: For I think thence might be made many happy Conjectures as to the Virtues of Plants. So where we see Plants, or Trees, of an open Pore growing low, we shall find their Juice has subtile Parts: So have all Vines, whether the Grape Vine, or Briony, or a Smilax, or the like. If a Gummous Plant or Tree, that grows low, and close Pored, it abounds with acid Spirits, as _Lignum Vitæ_, &c. if it grow tall, and be open Pored, it abounds with a subtile Volatile Spirit, as your Firs, and the Turpentine Tree. But to insist no further herein, than as this may be applicable to the present Discourse: For I have observed, that that which is called Pine-wood Land, tho' it be a sandy Soil, even the Sweet-scented Tobacco that grows thereon, being large and porous, agreeable to Aranoko Tobacco; it smoaks as coarsely as Aranoko: Wherefore 'tis,