Among People who are unacquainted with the Nature of Opium, it is a received Opinion,——That as it will, when taken in proper Doses, lull Pain, and procure Rest; so, in large Quantities, that it will terminate a Life of Cares, by an _easy_ and _quiet_ Death; but it is not so: this argument is directly contrary to the Nature of our Existence, the animal Oeconomy being so formed, as not to bear a total Solution, without some Agonies. Thus, when this Drug is received into the Stomach, in Quality of a Poison, easy Rest is denied, the Senses, roused by their threatened Solution, force the animal Powers into immediate Conflict with the noxious Body, which produces Convulsions, and other dreadful Symptoms, the Forerunners of Death.——The Drug is besides of so strong a Nature, that, though taken only into the Stomach, it can change the Colour of the Skin, and even of the Linen wore next it; a Body also, many Hours after Death, will smell so strongly of it, as to determine whether it was the Instrument of Destruction used. I might have encreased the Bulk of this Essay, by expatiating on the Effects of Opium upon the arterial Fluid; I could inform you, that the Power of it is diffused by the Stimulus of the recurrent Nerves, to their Origin in the Cerebellum, whence, by Consent of Parts, the whole System partakes of the Affect, and the contaminated Fluid is propelled by them, through the Heart into the Arteries, and communicated to the most distant Parts of the Body; also that the Skin is formed by very minute Fibres of the Nerves, interwoven with arterial Fibres and Veins, forming numerous Compages of secerning Vessels, &c. &c. but these are Subjects best suiting the medicinal Powers of Opium, which being derogatory from my Design, are purposely avoided, and, but that these Pages are for the Perusal of more than the Circle of Physical Gentlemen, the Cases alone would have been inserted, without even giving the natural History of the Drug; for this same Reason, the Prescriptions are set down in _English_, and the whole Essay disrobed of technical Expressions, as far as the Subject will allow. It will be thought, perhaps, that I have made too free with Dr. _Jones_, who is the only _English_ Author that has wrote professedly on this Subject; but many of his Sentiments being directly opposite to mine, I was under a Necessity of bringing them into an immediate Point of View. It is therefore hoped, no Person will be so unfriendly, as to impute to me a Malevolence of Disposition, which is a Character I would always diligently avoid. THE EFFECTS OF OPIUM, Considered as a POISON, &c.