ESSAY IV.
TheAncients having Experienced thatOpiumwould oftentimes Kill, though taken in no large quantity, ranked It withPoisons, and gave It the first place among Those, which from their Stupefying Quality They call’dNarcotic.
True indeed it is, that We do every Day find This to be, in a small Dose, one of the most Noble Remedies in the World. But it is not worth the while to engage in the Controversie warmly debated by someAuthors, how farPoisonsare Medicinal; since it is notorious enough, that Medicines do sometimes provePoisonous. And take the Matter as We please, it may serve to very good Purposes to understand the manner of Operation of so Celebrated aDrug, and help Us in a great Measure to ascertain Its Use in different Cases, if we are beforehand rightly apprised of Its Nature and Way of Acting.
In order hereunto, it is necessary, besides some otherPræcognita, since one of the chief Virtues of this Medicine IsHypnotic, to Define distinctly whatSleepis, or rather, (to avoid Confusion and Disputes about Words) what Difference there is between an Animal Body whenasleepand whenawake. For I suppose theHistory,Manner of Preparing, &c. ofOpium, to be already sufficiently known.
First then, There is no One but knows that inSleepthere is a Cessation from Action. WhenWaking, We Walk, Discourse, Move this or that Limb,&c.but in natural and undisturbedRestthere is nothing of all These; that is, whereas being awake, We do perform several Motions by thevoluntaryContraction of our Muscles; when asleep, those Muscles only are Contracted, whose Action is in a mannerInvoluntary, or to which the Mind has always so constantly determin’d the Spirits, that It does it by aHabit, without the Intervention of the Reasoning Faculty; such areThoseof the Heart and Breast.
So that there is at this time a kind ofRelaxationor Loosness of the moving Fibres of the several Members; or at least such a quiet Position and State of them, by which all theAntagonistMuscles are in anÆquilbriumand Equality of Action, not overpowering one another. For this indeed seems to be one great Design of Sleep, to recover to the Parts overstretched by Labour their formerToneand Force; and therefore we do naturally, when composing our selves toRest, put our Body into that Posture which does most Favour theparticularlywearied Limbs, and conduce to this end.
In the next place, it is very plain that there is inSleepnot only a Rest and Suspension from Acting of most of our Bodily Organs, but even of ourThinking Facultytoo. That is (for I would prevent Cavils) a ceasing from suchThoughtsas when Waking We are exercised about, which we doReflectupon, andWillto employ our Mind with. For thoughDreamsare Thoughts, yet they are but imperfect and incoherent Ones, and are indeed either so faint and languidRepresentations, as to be consistent with ourSleep, as some may be; or else if they be strong and lively, they are, as every one knows, theInterruptionand Disturbance of It.
From hence It will follow, That theMotionof the Arterial Fluid must be,Ceteris Paribus, more sedate, even and regular, in the time ofSleepingthanWaking; For, besides the various Alterations which in the latter State this receives from the severalPassionsof the Mind, the veryContractionsof the Muscles themselves in Exercises of the Body do differently forward its Course; whereas inSleepthe force of the Heart and Pectoral Muscles being more constant and uniform, gives it a more calm and equally continued Impulse.
Hence also it will come to pass, that theInfluxof theLiquorof the Nerves into the Organs of the Body, as also ItsRefluxtowards theBrain, is in Sleep either none, or very inconsiderable; that is, that this Fluid has at this time but little or noMotion. For ’tis MuscularActionandSensationthat require It to be thus determin’d, this way or that, which are now hardly any. And yet by the arrival of Blood at the Brain, thisJuicewill still be separated there, fit to be derived into its Canals or Tubes. So that by this means there will be a kind ofAccumulation, or laying up in Store, ofSpiritsfor the Offices and Requirements ofWaking.
Thus We may in short look upon the time ofWatching, as the time of Wearing out, or the Destruction of the Animal Fabrick; and the time ofSleep, as that in which it is repaired and recruited; not only upon the account of what We have just mentioned concerning theNervous Liquor, but also with respect to all the other Parts, as well Fluid as Solid. ForActiondoes necessarily by Degrees impair the Springs and Organs; and inMotionsomething is continually abraded and struck off from the Distractile Fibres, which cannot otherwise be restored than by their being at rest fromTension. Besides that, such a regular and steadyCourseof the Blood, as we have observed to be inSleep, is by far more fit and proper for Nutrition, or an Apposition of Parts to the Vessels, which an unevenHurryof It is more apt to tear off and wash away.
The Case being thus, it is very plain that whatsoever can induce such a Disposition of the Fluids and Muscular Parts of the Body, as this We have described, will so far causeSleepiness. And in like manner, when any thing interposes and hinders this Composedness and Tranquillity, the removing of theImpedimentwill be the causing ofSleep; inasmuch as this is only reducing the AnimalŒconomyto its right State, in which by natural Order there must be a Succession of Sleeping and Waking.
Thus it appears how necessarily continued Exercises do make UsSleepy, since These do exhaust the Juice of the Nerves; that is, both lessen its Influx into the Organs of Motion, and incline the Mind not to determine it any longer that way, upon the account of the Pain and Uneasiness, with which too violent a Tension of the Parst is always attended; which therefore we must needs desire to Relax, or lay toRest.
ThatSleepinesswhich follows upon a fulness of the Stomach after Eating or Drinking, is owing to a different Cause; and does indeed so nearly fall in with the Effects ofOpiateMedicines, that it requires a particular Consideration.
AsHunger, or the Emptiness of the Stomach, is a painful Sensation; so the satisfying or removing ofThis, is a pleasing or agreeable One. Now allPainis aStimulusupon the Part affected; and This, we all know, being attended with Contractions of the pained Membranes, causes a greater Afflux than ordinary of the Nervous Juice that way. On the other Hand,Pleasure, or a delightful Sensation in any part, is accompanied with a smooth Undulation, and easie Reflux of the Liquor of the Nerves towards the Brain. This is, as it were, theEntertainmentof the Mind, with which beingTaken up, it does not Determine the Spirits to the Organs of Motion; That is, there is such aRelaxationof the Muscular Fibres, and such a Disposition of the Nervous Fluid, as we have observed to be necessary to Sleep.
This is the Reason of thatChillinessin the Limbs, which we commonly Complain of after a good Feast.
If it seem strange that a Pleasure in the Stomach should so powerfully Influence the Mind; let it be considered, on the other Hand, how violent Effects, an uneasie and disagreeable Sense in the same Part does produce; what a terrible Agony Two or Three Grains ofCrocus Metallorumthrows the whole Fabrick into; how readily the Fluid of the Nerves is with a more than OrdinaryImpetusdetermin’d and commanded into the Muscles of the Stomach andAbdomen, in order to throw off the Enemy, and remove the ungrateful Sensation.
Now the Consequences which we have ascribed to a pleasing Sense in this Part, are only just the contrary of these we find the opposite Affection of Pain induces. And indeedPleasureandPainare Two great Springs of Action in the Animal Œconomy; The Changes they make in the Fabrick are the Causes of many Effects which seem surprising, because we do not regard the Mechanism by which they are produced: but these must be more considerable in the Stomach than any where else; This Part being, for very wise Purposes, of so acute aFeeling, that some Philosophers have for this Reason thought It to be the Seat of the Soul.
Besides this Consideration, We must take notice that, the Stomach being distended with Food, presses upon the descendingTrunkof theAorta, and thus causes a greater Fulness of the Vessels in the upper Parts; whereupon the Brain is loaded, or the Derivation of Spirits into the Nerves diminished, andUnactivityorDrowsinessinsues. From hence proceed ThoseFlushingsin the Face, Redness,&c.after plentiful Eating or Drinking, most Visible in Those whose Vessels are Lax and Weak, as in Exhausted and Hectick Persons they more especially are.
Thus we may, without the Assistance of theNew Chyleentring into the Vessels, account for that Inclination to Sleep which follows upon a full Stomach; Tho’ we must also allow the Distension fromThisto be a considerable Cause of the same Effect; But this does not happen immediately, nay, sometimes perhaps not within Two or Three Hours after Eating; and therefore the suddenDrowsinessmust (as well as the present Refreshment and Reviving which Meat gives) be chiefly owing to some more speedy Alteration.
We come then in the next Place toOpiumit self; The ChymicalAnalysisof which(147)does out of One Pound afford of a VolatileSpiritof the like Nature with that drawn from Harts-horn, Five Ounces and Five Drachms; of a fætidOil, One Ounce Two Drachms and a half; ofCaput Mortuum, smelling like Spirit of Harts-horn, Seven Ounces and Six Drachms.
The Virtues therefore ofOpiumare owing to a volatileAlcalineSalt, intimately mixt and combin’d with an Oily, Sulphureous Substance. The Effects of which We must consider, first of all upon the Stomach, and afterwards, when they have passed thePrimæ Viæ, upon the Arterial Fluid it self.
An agreeable Sensation produced in the Stomach, together with a Distension of Its Membranes, we observed before to be the Cause of that Sleepiness to which we are so prone after Eating. TheOneof These ingages the Mind, theOtheracts upon the Body. For Pleasure amuses the Soul, as it were, so that It does not Think, or exercise it self about any outward Objects; that is, Is inclined to Rest. And the Fulness of the Vessels in the Brain Checks and Hinders, in some Measure, the Derivation of the Nervous Juice into the Organs,&c.
Now They who take a moderate Dose ofOpium, especially if not long accustomed to It, are so Transported with the pleasing Sense It induces, that They are, as They oftentimes express themselves, in Heaven; and tho’ They do not always Sleep, (which proceeds from the Presentation of pleasing Images to the Mind being so strong, that like Dreams they do over-ingage the Fancy, and so interrupt the State of Rest) yet they do however injoy so perfect an Indolence and Quiet, that no Happiness in the World can surpass the Charms of this agreable Extasie.
Thus We have from this Medicine, but in a far more eminent Degree, all those Effects which we observed to follow upon that grateful Sense in the Stomach, which a moderate Fulness produces. For no Bodies are so fit and able pleasingly to affect our sensile Membranes, as Those which consist of Volatile Parts, whose activity is tempered and allayed by the smoothness of some Lubricating and Oily ones; which by lightly Rarefying the Juices of the Stomach, and causing a pleasant Titillation of Its Nervous Coat, will induce an agreablePlenitude, and entertain the Mind with Ideas of Satisfaction and Delight.
The Case being thus, We easily see upon what Mechanism the other Virtues ofOpiumdo depend, Its Easing Pains, Checking Evacuations,&c.not only in that the Mind being taken up with a pleasing Sense, is diverted from a disagreableOne; But all Pain being attended with a Contraction of the Part, That Relaxation of the Fibres which is now caused, eludes and destroys the Force of theStimulus.
In like manner in immoderate Secretions there is most commonly an Irritation of the Organs, the Removal of which will abate the Discharge. And herein lies theIncrassatingQuality of this Medicine, in that the Twitching Sense upon the Membranes of the Lungs, Bowels,&c.being now lessened, the sharp Humor is suffered to lodge there in a greater quantity, before it is so troublesome as to be thrown off and expell’d; it being all one as if there were no Irritation of the Part, if the uneasie Sense thereof be not regarded by the Mind.
These Effects will all be heightened by the Mixture of theOpiateParticles with theBlood; Which is hereupon Rarefied, and Distends its Vessels, especially those of the Brain; and thus does still to a greater Degree lessen the Influx of the Nervous Fluid to the Parts, by pressing upon the littleTubuli, or Canals, thro’ which it is derived.
This is the Reason of thatDifficulty of Breathing, which they do for a time Experience who take these kind of Medicines; This Symptom being inseparable from the Rarefaction of the Blood in the Lungs.
From hence it appears, that the Action ofOpiumis very Analogous to that of other Volatile Spirits, only that a small Portion of It has a force equal to that of a greater quantity of most of Them.
This is very evident in Those who accustom Themselves to take large Doses of It; as theTurksandPersiansdo to that Degree, that it is no uncommon thing there to Eat a Drachm or Two at a time; for the Effects of It in Them are no other than downrightDrunkenness; upon which account(148)it is as common a Saying with Them, and on the same Occasion,He has eat Opium; as with Us,He has drank too much Wine.
Neither indeed do They otherwise bear such large quantities of It, than ourTipplerswill a great deal ofBrandy; that is, by habituating themselves to It by degrees, beginning with small Doses, and requiring still more and more to raise themselves to the samePitch. Just asGalen(149)tells Us of a Woman atAthens, who by a gradual Use had brought her self to Take, without any hurt, a considerable quantity ofCicutaor Hemlock. Which Instance is the more to our Purpose, becauseNic. Fontanus(150)knew one who being Recovered of the Plague, and wanting Sleep, did, with very good Effect, eatHemlockfor some time, till falling Ill again of a Fever, and having left off the Use of this Remedy, He indeavoured to procure Rest by repeated Doses ofOpium, which (Nature having been accustomed to a stronger Alterative) had no Operation, till the help ofCicutawas again call’d in with desired Success.
It is a sufficient Confirmation of all this Reasoning, thatProsper Alpinus(151)observed among theEgyptians, those who had been accustom’d toOpium, and were faint and languid thro’ want of It, (as Drinkers are if they have not theirSpirits) to be recovered, and put into the same State of Indolence and Pleasure, by large Doses ofCretic Winemade hotter by the Infusion ofPepper, and the like strongAromatics.
Nor is it perhaps amiss to remark, that inManiacalPeople, as is frequently observ’d, a Quadruple Dose ofOpiumwill scarce produce any considerable Effect: Now in Persons so affected, the Mind is deeply ingaged and taken up with someImagesor other, as Love, Anger,&c.so that it is not to be so easily moved or diverted by those pleasing Representations which it would attend to at another time, and upon which the Virtues of this Medicine do in a great measure depend. Besides this, those who areManiacaldo to a Wonder bear the Injuries of Cold, Hunger,&c.and have a prodigious degree of Muscular Force, which argues the Texture of theirBloodto be very strong, and the Cohæsion of itsGlobulesgreat; so that the Spirituous Parts of theOpiatecannot make that Disjunction and Rarefaction of this Fluid in Them, which it does in ordinary Bodies and Constitutions.
Many are the Immprovements which might be made of this Theory, with relation to the Practice of Physick; but these will be obvious enough to one instructed in the AnimalŒconomy.
To conclude then as to the Subject in Hand, it is very plain that there needs no more to makeOpiumprove Destructive or aPoison, than to take too great a quantity of It; for then It must Inflame the Stomach, and Rarefie the Blood to such a Degree, that the Vessels cannot again recover their Tone, whereupon Apoplectic Symptoms,&c.will insue.
To be convinced of this, I forced into the Stomach of a small Dog about half a Drachm of CrudeOpiumdissolved in Boiling Water. He quickly Vomited It up with a great quantity of Frothy Spittle; but repeating the Trial, by holding up his Head, and beating him, I made him retain Three or Four Doses, intermitting between each about a quarter of an Hour; when he had thus taken, as I could guess, near Two Drachms, I watch’d him about an Hour, then he began to Sleep, but presently started up with Convulsions, fell into universal Tremblings, his Head constantly twitch’d and shaking, he breath’d short and with labour, lost intirely the Use first of his hinder Legs, and then of the fore ones, which were stiff and rigid like Sticks. As he lay Snorting, to hasten his End, I was giving him more of the Solution, but on a sudden his Limbs grew limber, and He Died.
Opening hisStomach, I found It wonderfully distended, tho’ empty of every thing but some Water andOpium; parcels of FrothyMucusswimming in It; the inside was as clean as if scraped and washed from all the Slime of the Glands, with some Redness here and there, as in a beginning Inflammation. ThePyloruswas Contracted. The Blood-Vessels of the Brain were very full; and I took out a large Grume of Concrete Blood from the upper part of It, cutting into theSinus Longitudinalis, as is not uncommon in Apoplectic Carcasses; but found no extravasatedSerumin theVentricles, nor among any of the Membranes.
As to the Cure of such a Case; besides other Evacuations, Acid Medicines and Lixivial Salts must certainly do Service; these by theirDiureticforce causing a Depletion of the Vessels. This is the Foundation upon whichStarkycompounded hisPacific Pill. GenerousWine, which the Ancients gave for an Antidote, can be no other ways useful, than as It dissolves theResinousClammy Part of theOpiumsticking to the Coats of the Stomach, and so forwards its Expulsion by other Helps, which cause a Contraction of the Muscular Fibres.