The mysteries of opium reveal'd by Dr. John Jones ... ; who, I. Gives an account of the name, make, choice, effects, &c. of opium, II. Proves all former opinions of its operation to be meer chimera's, III. Demonstrates what its true cause is, by which he easily, and mechanically explains all (even its most mysterious) effects, IV. Shews its noxious principle, and how to separate it, thereby rendering it a safe, and noble panacea, whereof, V. He shews the palliative, and curative use.

CHAP. XII. Shews what must be the true Cause of the Ope∣ration of Opium. (Book 12)

ALL the general Foundations upon which Au∣thors, either Ancient or Modern, erected their several Hypothesises concerning the Operation of Opium, having (as manifestly appears) no real Existence; What Enchanted Castles in the Air, or vain Phantasms, must their Structures be? And, how like deluded Wizzards must they appear, while they seem'd to take high Flights and glorious Prospects of Causes that had no Reality?

Thus am I left utterly distitute of either Foun∣dation or Model, unless I find out that, and frame this; which (I hope) may be easily done, be∣cause (the cloudy Supposition of Vapours having va∣nished away) there now remains but Two Ways by which an Internal Medicament can Operate, viz.

• 1. As an Alterative of the Blood, &c. Or,
• 2. As affecting the Sense of Feeling, either grie∣vously, as Vomits, Purgers, &c. Or pleasingly, as Cordials, generous Wines, titillating Amphrodisiacks, comfortable Warmth, Anodynes, and such like, that please the Nerves and Membranes; which way of Operating is too little observ'd by Physicians, tho' they take great Notice of the Operation of Things by grievous Sensation, as Irritatives to Vomit, Purge, Salivate, &c. by their Acrimony; whereas the Pleasers of Sensation, which must, as Contraries, have contrary Operations, are little regarded, or thought of.

1. Opium does not Operate as an Alterative of the Bloud, &c.

First, Because it Operates while it is at Stomach, or (at least) before it arrives at the Bloud; which manifestly appears several Ways; as,

• 1. Because it often Operates in a Liquid Form in few Minutes, and very commonly in a Quarter of an Hour, in which time it must be at Stomach, or, at least, far from arriving at the Bloud.
• 2. Because it has been very often Vomited up after it has Operated, and produced its usual Ef∣fects for 1, 2, 3, 4, 5, 6, 8, 10, and sometimes more Hours; as evidently appear'd by the Smell, Colour, Taste, &c. of what was Vomited; and by its Operation ceasing after such Vomiting; of which common Experience, and Authors, do inform us: See Helmont Ius Duumvir. 62. where he tells of Opium Operating at Night, and Vomited up next Morning.
• ...

  3. Its bare causing Vomiting after it has Ope∣rated for a good while, is of it self (tho' its Taste, Smell, &c. did not discover it) an infallible Argu∣ment of its Operating, while it is at Stomach; for 'tis against all Reason to imagine, that Things should irritate it to Vomit after they are gone into the Bloud, and not do it while they are in the Stomach it self, as all Vomitories do.

  The Reasons why it stays so long at Stomach, are, 1. Its Indigestibleness, which plainly appears by Stools, Urine, and Sweat, smelling of it, when taken in any considerable Quantity; all the Cocti∣ons, Digestions, Circulations, &c. that it passes in the Body, signifying very little to it, which its causing Itchings in the Skin, and affecting the Ve∣nereal

• ...

  Membranes after its passing the Bloud, do also argue. 2. The clamminess of its resinous Parts sticking to the Stomach, cause (as I shall plainly prove hereafter) its long stay in it; for if the Rosin be separate from it, 'twill not then make such a long stay at Stomach, as I have often Ex∣perienced.

• 4. We actually feel it causing a sense of Plea∣sure at Stomach during its Operation, therefore it is then in it.
• 5. It has been carried off by Stool after it has produced its usual Effects; Therefore it Operated before it arrived at the Bloud.
• ...

  6. All Observers do allow, that Opium Ope∣rates while it is at Stomach; which gave the Oc∣casion (as you may remember) to the Hypothesis of its Operating by Fumes rising out of the Sto∣mach; because they could not think of any other Means by which it might affect the Head, Brain, Animal Spirits, Nerves, &c. while it was at Sto∣mach, but by the Way of Fumes or Vapours.

  It is therefore past all doubt, That Opium pro∣duces its common Effects while it is at Stomach, and before it arrives at the Blood, and therefore does not Operate as an Alterative thereof.

Secondly, Because a Grain of Opium, which Ope∣rates very remarkably, bears (as Etmuller well observes) so small a Proportion to the Bloud, that it cannot produce such great, and notable Effects, as an Alterative thereof; for a Grain of Opium to 20 Pound of Blood, (which an ordi∣nary Man has in his Body) is but as 1 to 115200, or (if 16 Oucnes be allow'd to the Pound) as 1 to 153600. But it is no Wonder if a Grain should affect the Membrane at Stomach, since the

1000 part of a Grain of the Vomitory Particles of Crocus Metallorum, or Regulus of Antimony, does affect it so eminently, as many other Things will in a very small Quantity; whereas the altering of the Blood to any observable degree, requires the Use of Alteratives in great Quantity for seve∣ral Weeks: Which confirms the former Conclu∣sion, That Opium does not Operate as an Alterative, as to its common and usual Effects.

II. Opium does not Operate by grievous Sensation, (or Irritation) as Vomits, Purgers, Errhines, Sali∣vators, (or Apophlegmatizers) &c. do.

First, Because it manifestly causes a very agree∣able, pleasant, and even charming Sensation.

Secondly, Because it takes away grievous Sensa∣tion or Pain, thereby stopping Vomiting, Purging, and all other-Effects of grievous Sensation, by Acri∣mony, &c.

As for the Vomiting that Opium sometimes causes, it is only (as shall be shewn) by its Resinous Parts sticking to the Coat of the Stomach, which being separated from it, Opium has no such Effect, tho' all its good Effects remain. So its Purging (which happens most rarely, and only when a great Quantity is given to Men of strong Digestion) it is only from its Rosin digested, and resolved in strong Stomachs; Hence it is that Dogs, and such as have canine Appetites, do generally Purge after a great Quantity of Crude or Rosinous Opium; whereas such as is not Rosinous causes no such Effect. But of these Matters more to your Satisfaction hereafter.

Thirdly, Because it causes all Effects that are quite contrary to those of grievous Sensation; It

causing an Ovation of the Sensitive Soul and Spi∣rits; Pain (or grievous Sensation) a Depression of Spirits; It causing Euphory and Pain, Weariness; For what tires more than Pain, or labouring in Pain? It causing good Humour, Pain Peevishness, Fretfulness, and ill Humour; Opium causing Relaxa∣tion of all Parts, Pain Contraction; That causing free Perspiration, this checking it; That causing Sleep, this hindering it; That causing Conten∣tation Acquiescence, this Discontent and Uneasi∣ness; That composing, this discomposing the Spi∣rits, Bloud, &c. That causing Fluxes by Irritati∣on, &c. this moderating, or stopping them; That opening the Pores, Pain constringing them; Opium preventing the Shaking Fits in Agues, Pain bringing them on; That causing a large and slow Pulse, this a quick, hard, and narrow Pulse; That causing an Efflorescence of the Skin, this Pale∣ness; That pleasant, this unpleasant Dreams; That stills Hiccoughs, this causes them; That takes off Contractions, Convulsions, &c. this causes them. To be short, Opium causes all the Effects of pleasant Sensation, and takes off all the Effects of grievous Sensation. What can be a more evi∣dent Proof of its acting by causing a pleasant Sensation? It were endless to mention all the Proofs that may be made to the same Purpose, from Pleasers and Displeasers of Sensation.

Therefore we fairly conclude,

That Opium does not Operate by causing a grievoui Sensation, and there being no other Way left by which it may Operate,

It must Operate by causing a pleasant Sensation; which is the true and plain Reason why (as has been shewn) it takes off Pain, and causes all Effects quite contrary to that of grievous Sensation;

Irritations by Acrimony, &c. which are most eminent upon the most sensible Parts, as the Sto∣mach, Intestines, Venereal Membranes, Skin, &c. as you may observe where the Effects of Opium are enumerated.

Now (gentle Reader) consider, That Contraries are the true Cure of Contraries: What can then cure Pain, and all its Effects, better than Pleasure? 'Tis very strange then, that Millions for many Ages finding Opium cure, or take off Pain, and all its Effects, above all Things, should not attri∣bute its so doing to its causing a pleasant Sensation, which is the direct contrary to Pain, especially since every Man that took Opium felt an actual Pleasure upon taking thereof, pleasant Dreams, a pleasant Humour, &c.

It may be said, What if it be granted, that O∣pium Operates by a pleasing Sensation, (which I will Thank none for, that have Feeling at Stomach, or Reason at Brain) how is it possible that such pleasant Sensation should cause and explicate all the various, strange, wonderful, mysterious, and very often seemingly contradictory Phenomena's and Effects of Opium?

Answer. As easily as ever I explain'd any Thing in Nature, especially if my Tract of Ani∣mal Mechanism were published; but it is my Mis∣fortune that it is not, however it shall not be the Readers, tho' it will put me to a great Trouble; To evade which, is none of my Intention, by those Words, but rather to bespeak the Reader's Patience while I am premising some necessary Praecognita requisite to be known before I enter upon the Explication of the wonderful and seemingly inex∣plicable Effects of Opium.

I therefore desire the Reader's Leave to premise some Things of the Nature of Sensation, and sensitive Pleasure, in order to his more clear and ready Understanding my Explication of this My∣sterious and Momentous Matter, look'd upon as so dark and abst••use a Business to this day, that some have not only yielded it up as a Thing hidden from Mankind, but have earnestly and seriously argued, that it acted absolutely by an occult Quality, reserved in a special manner (as is the Nature of Spirits) from our Knowledge.

That it has been so hitherto, I think none can deny, as the Circulation of the Bloud was for Thousands of years, tho' the very Motion was seen by Millions; so as the Cause of the Operation of Opium has been felt by a far greater number, it therefore will (if I fail not in explaining it) appear so clear, that it will be much wondered at (like that of the Circulation of the Bloud) why so obvious a Thing was not found by every one that used Opium. But (whatever Opium is) God's Methods are unsearchable, and often his Wise Providence bestows good Gifts upon the Un∣worthy, that his free Goodness may appear; To whom be all Glory, Praise, and Thanksgiving for ever and ever. Amen.

Note, That while I am upon the Preparatory Discourse about Sensation, Pleasure, &c. in the fol∣lowing Chapters, you may sometimes wonder what I would be at, because you may not per∣ceive the Drift, yet do they require your Atten∣tion as being the Foundation of all that is to follow; which you'll plainly perceive afterward, when (I hope) you'll have good Satisfaction for your pa∣tient and attentive Perusal of the Two following Chapters.