Chapter IV: Part 4

First then, There is no One but knows that in _Sleep_ there is a Cessation from Action. When _Waking_, We Walk, Discourse, Move this or that Limb, _&c._ but in natural and undisturbed _Rest_ there is nothing of all These; that is, whereas being awake, We do perform several Motions by the _voluntary_ Contraction of our Muscles; when asleep, those Muscles only are Contracted, whose Action is in a manner _Involuntary_, or to which the Mind has always so constantly determin’d the Spirits, that It does it by a _Habit_, without the Intervention of the Reasoning Faculty; such are _Those_ of the Heart and Breast.

So that there is at this time a kind of _Relaxation_ or Loosness of the moving Fibres of the several Members; or at least such a quiet Position and State of them, by which all the _Antagonist_ Muscles are in an _Æquilbrium_ and 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 former _Tone_ and Force; and therefore we do naturally, when composing our selves to _Rest_, put our Body into that Posture which does most Favour the _particularly_ wearied Limbs, and conduce to this end.

In the next place, it is very plain that there is in _Sleep_ not only a Rest and Suspension from Acting of most of our Bodily Organs, but even of our _Thinking Faculty_ too. That is (for I would prevent Cavils) a ceasing from such _Thoughts_ as when Waking We are exercised about, which we do _Reflect_ upon, and _Will_ to employ our Mind with. For though _Dreams_ are Thoughts, yet they are but imperfect and incoherent Ones, and are indeed either so faint and languid _Representations_, as to be consistent with our _Sleep_, as some may be; or else if they be strong and lively, they are, as every one knows, the _Interruption_ and Disturbance of It.

From hence It will follow, That the _Motion_ of the Arterial Fluid must be, _Ceteris Paribus_, more sedate, even and regular, in the time of _Sleeping_ than _Waking_; For, besides the various Alterations which in the latter State this receives from the several _Passions_ of the Mind, the very _Contractions_ of the Muscles themselves in Exercises of the Body do differently forward its Course; whereas in _Sleep_ the 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 the _Influx_ of the _Liquor_ of the Nerves into the Organs of the Body, as also Its _Reflux_ towards the _Brain_, is in Sleep either none, or very inconsiderable; that is, that this Fluid has at this time but little or no _Motion_. For ’tis Muscular _Action_ and _Sensation_ that 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, this _Juice_ will still be separated there, fit to be derived into its Canals or Tubes. So that by this means there will be a kind of _Accumulation_, or laying up in Store, of _Spirits_ for the Offices and Requirements of _Waking_.

Thus We may in short look upon the time of _Watching_, as the time of Wearing out, or the Destruction of the Animal Fabrick; and the time of _Sleep_, as that in which it is repaired and recruited; not only upon the account of what We have just mentioned concerning the _Nervous Liquor_, but also with respect to all the other Parts, as well Fluid as Solid. For _Action_ does necessarily by Degrees impair the Springs and Organs; and in _Motion_ something is continually abraded and struck off from the Distractile Fibres, which cannot otherwise be restored than by their being at rest from _Tension_. Besides that, such a regular and steady _Course_ of the Blood, as we have observed to be in _Sleep_, is by far more fit and proper for Nutrition, or an Apposition of Parts to the Vessels, which an uneven _Hurry_ of 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 cause _Sleepiness_. And in like manner, when any thing interposes and hinders this Composedness and Tranquillity, the removing of the _Impediment_ will be the causing of _Sleep_; inasmuch as this is only reducing the Animal _Œconomy_ to 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 Us _Sleepy_, 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 to _Rest_.

That _Sleepiness_ which 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 of _Opiate_ Medicines, that it requires a particular Consideration.

As _Hunger_, or the Emptiness of the Stomach, is a painful Sensation; so the satisfying or removing of _This_, is a pleasing or agreeable One. Now all _Pain_ is a _Stimulus_ upon 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, the _Entertainment_ of the Mind, with which being _Taken up_, it does not Determine the Spirits to the Organs of Motion; That is, there is such a _Relaxation_ of 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 that _Chilliness_ in 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 of _Crocus Metallorum_ throws the whole Fabrick into; how readily the Fluid of the Nerves is with a more than Ordinary _Impetus_ determin’d and commanded into the Muscles of the Stomach and _Abdomen_, 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 indeed _Pleasure_ and _Pain_ are 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 a _Feeling_, 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 descending _Trunk_ of the _Aorta_, 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, and _Unactivity_ or _Drowsiness_ insues. From hence proceed Those _Flushings_ in 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 the _New Chyle_ entring into the Vessels, account for that Inclination to Sleep which follows upon a full Stomach; Tho’ we must also allow the Distension from _This_ to 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 sudden _Drowsiness_ must (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 to _Opium_ it self; The Chymical _Analysis_ of which (147) does out of One Pound afford of a Volatile _Spirit_ of the like Nature with that drawn from Harts-horn, Five Ounces and Five Drachms; of a fætid _Oil_, One Ounce Two Drachms and a half; of _Caput Mortuum_, smelling like Spirit of Harts-horn, Seven Ounces and Six Drachms.

The Virtues therefore of _Opium_ are owing to a volatile _Alcaline_ Salt, 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 the _Primæ 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. The _One_ of These ingages the Mind, the _Other_ acts 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 of _Opium_, 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 agreable _Plenitude_, and entertain the Mind with Ideas of Satisfaction and Delight.

The Case being thus, We easily see upon what Mechanism the other Virtues of _Opium_ do depend, Its Easing Pains, Checking Evacuations, _&c._ not only in that the Mind being taken up with a pleasing Sense, is diverted from a disagreable _One_; 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 the _Stimulus_.

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 the _Incrassating_ Quality 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 the _Opiate_ Particles with the _Blood_; 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 little _Tubuli_, or Canals, thro’ which it is derived.

This is the Reason of that _Difficulty 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 of _Opium_ is 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 the _Turks_ and _Persians_ do 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 downright _Drunkenness_; 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 our _Tipplers_ will a great deal of _Brandy_; that is, by habituating themselves to It by degrees, beginning with small Doses, and requiring still more and more to raise themselves to the same _Pitch_. Just as _Galen_ (149) tells Us of a Woman at _Athens_, who by a gradual Use had brought her self to Take, without any hurt, a considerable quantity of _Cicuta_ or Hemlock. Which Instance is the more to our Purpose, because _Nic. Fontanus_ (150) knew one who being Recovered of the Plague, and wanting Sleep, did, with very good Effect, eat _Hemlock_ for 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 of _Opium_, which (Nature having been accustomed to a stronger Alterative) had no Operation, till the help of _Cicuta_ was again call’d in with desired Success.

It is a sufficient Confirmation of all this Reasoning, that _Prosper Alpinus_ (151) observed among the _Egyptians_, those who had been accustom’d to _Opium_, and were faint and languid thro’ want of It, (as Drinkers are if they have not their _Spirits_) to be recovered, and put into the same State of Indolence and Pleasure, by large Doses of _Cretic Wine_ made hotter by the Infusion of _Pepper_, and the like strong _Aromatics_.

Nor is it perhaps amiss to remark, that in _Maniacal_ People, as is frequently observ’d, a Quadruple Dose of _Opium_ will scarce produce any considerable Effect: Now in Persons so affected, the Mind is deeply ingaged and taken up with some _Images_ or 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 are _Maniacal_ do to a Wonder bear the Injuries of Cold, Hunger, _&c._ and have a prodigious degree of Muscular Force, which argues the Texture of their _Blood_ to be very strong, and the Cohæsion of its _Globules_ great; so that the Spirituous Parts of the _Opiate_ cannot 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 Animal _Œconomy_.

To conclude then as to the Subject in Hand, it is very plain that there needs no more to make _Opium_ prove Destructive or a _Poison_, 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 Crude _Opium_ dissolved 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 his _Stomach_, I found It wonderfully distended, tho’ empty of every thing but some Water and _Opium_; parcels of Frothy _Mucus_ swimming 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. The _Pylorus_ was 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 the _Sinus Longitudinalis_, as is not uncommon in Apoplectic Carcasses; but found no extravasated _Serum_ in the _Ventricles_, 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 their _Diuretic_ force causing a Depletion of the Vessels. This is the Foundation upon which _Starky_ compounded his _Pacific Pill_. Generous _Wine_, which the Ancients gave for an Antidote, can be no other ways useful, than as It dissolves the _Resinous_ Clammy Part of the _Opium_ sticking to the Coats of the Stomach, and so forwards its Expulsion by other Helps, which cause a Contraction of the Muscular Fibres.

FOOTNOTES to Essay IV.

(147) Vid. _Pitcarn. de Circulasione Sanguinis in animalibus_, §. 20.

(148) Vid. _Belon. Voyag._ lib. 3. c. 15.

(149) _Simpl. Medicam. Facult._ l. 3. c. 18.

(150) _Respons. & Curat. Medic._ p. 162.

(151) _Medicin. Ægypt._ l. 4. c. 1.

ESSAY V.

Of Venomous Exhalations from the EARTH, Poisonous Airs and Waters.

Besides these already treated of, there is yet another way of being _Poisoned_, and that is by _Venomous Steams_ and _Exhalations_, or a _Poisonous Air_ taken into the Body by the Breath.

This is notorious enough, and Authors do upon many Occasions make mention of it; but when they come to explain the particular manner how this Kills, they most commonly reduce it to some of the _Poisons_ which prove destructive by being admitted into the Stomach, alledging that Malignant Fumes and Airs are therefore fatal, because impregnated with _Arsenical Mercurial_, and the like, Deleterious Μιάσματα or Particles, they do convey these into the Blood; which being of a very Corrosive Nature, must necessarily do hurt both to the Fluid and Solid Parts.

And indeed that the _Fumes_ of these same Minerals are very pernicious, and Air fill’d with their Atoms very unfit for Respiration, is most certain; but to argue from hence, that all deadly _Vapours_ and Malignant _Airs_ owe their Mischief to these only, is too fond and ill-grounded a Conceit; since upon a due Enquiry it will appear, that there may be, and are, _Mortiferous Exhalations_ from the Earth, infecting the Air, of a Nature so different from any of those _Poisons_, that the very Substance from which they arise may not be at all hurtful, tho’ taken into the Stomach it self.

_Venomous Steams and Damps_ from the Earth the _Latins_ in one Word call’d _Mephites_ (152).

This, as many other _Tuscan_ Words, comes from a _Syriac_ Theme, which signifies to blow or breathe (153).

And in ancient times several Places were notorious for ’em; so the _Mephitis_ of _Hierapolis_ was very Famous, of which _Cicero_, _Galen_, but more particularly, and from his own Sight and Knowledge _Strabo_ (154) makes mention.

Such another was the _Specus Corycius_ in _Cilicia_, which upon the account of its stinking deadly Air, such as is thought to proceed from the Mouth of _Dragons_, which the Poets give to _Typhon_, was call’d _Cubile Typhonis_. This _Pompon. Mela_ (155) describes; and it is indeed as ancient as _Homer_ (156); for _Arima_, in which he places it, was, as _Eustathius_ says, a Mountain of _Cilicia_.

Neither are such _Fumes_ as these infrequent Now-a-days; and though mostly taken notice of in Mines, Pits, and other Subterraneous Places, yet they are sometimes met with in the Surface of the Earth too, especially in Countries fruitful of Minerals, or pregnant with Imbowelled Fires; such are _Hungary_ and _Italy_, which latter (as _Seneca_ (157) observes) has always been more than any other remarkable for ’em.

I shall therefore, having had the opportunity of making some Remarks upon One the most Famous of all in those Parts, give as good an account as I can of _That_, and its manner of Killing; which tho’ I dare not affirm to be universally applicable to any _Mephitis_ whatsoever, yet seems plainly to be the Case of most of ’em; and where it is not, this simple Mischief will only be found to be complicated with another; and then some extraordinary Symptoms or Appearances in the Animals kill’d, will easily make a Discovery of the Additional Venom and Malignity.

This Celebrated _Mofeta_ taken notice of, (or at least some other hereabouts) even in the time of _Pliny_ (158), is about Two Miles distant from _Naples_, just by the _Lago d’ Agnano_, in the way to _Pozzoli_ or _Puteoli_, and is commonly call’d _la Grotta de Cani_, because the Experiment of its deadly Nature is frequently made upon _Dogs_; tho’ it be as certainly fatal to any other Animal, if it come within the reach of its Vapour; for _Charles the Eighth of_ France prov’d it so upon an _Ass_; and two _Slaves_ put into it by order of _D. Pietro di Toledo_, Viceroy of _Naples_, with their Heads held down to the Earth, were both kill’d (159).

’Tis a small _Grotta_ at the Foot of a little Hill, about Eight Foot high, Twelve long, and Six broad; from the Ground arises a thin, subtle, warm _Fume_, visible enough to a discerning Eye, which does not spring up in little parcels here and there, but is one continued Steam, covering the whole Surface of the bottom of the Cave; and has this remarkable difference from common Vapours, that it does not, like Smoak, disperse it self into the Air, but quickly after its rise falls back again, and returns to the Earth; the Colour of the sides of the _Grotta_ being the measure of its Ascent; for so far it is of a darkish Green, but higher, only common Earth, and this is about Ten Inches. And therefore as my self found no Inconvenience by standing in it, so no Animal if its Head be kept above this Mark is in the least injured: But when (as the manner is) a Dog, or any other Creature, is forcibly held below it, or by reason of its smalness can’t hold its Head above it, It presently, like one stunn’d, loses all Motion, falls down as Dead, or in a Swoon, the Limbs convuls’d and trembling, till at last no more sign of Life appears than a very weak and almost Insensible beating of the Heart and Arteries, which if the Animal be left there a little longer, quickly ceases too, and then the Case is Irrecoverable; But if snatch’d out, and laid in the open Air, soon comes to Life again, and sooner if thrown into the adjacent _Lake_.

In this short, but accurate, History of the _Grotta de Cani_, I have set dow those Particulars which do not only distinguish _Mephitical_ Exhalations from common and innocent Fumes, but also give hints sufficient, I think, Mechanically to determine the Reason and Manner of their surprising Effects.

And not to spend time in refuting the Opinions of Others, I shall only take Notice, that here can be no suspicion of any true _Venom_ or real Poison; if there was, it were impossible that Animals taken out of the _Grotta_, should so immediately recover the Effects of it, without any remaining appearance of Faintness and Sickness, or such like Symptoms as those suffer who have been breathing in an Air impregnated with malignant corrosive _Effluvia_. Besides, that the Venomous Corpuscles would certainly, in some Degree at least, infect the Air in the upper Part of the Cave, which continues pure, and fit for Respiration. Neither indeed after what manner soever this Poison be imagin’d to Act, whether by dissolving or coagulating the Blood, could its Efficacy be so sudden and momentaneous, without some Marks of it in the Creatures kill’d, when opened, which yet do discover nothing of this Nature extraordinary, neither in the Fluid, nor in the Solid Parts.

In order therefore to understand wherein this deadly quality Consists; I say in the first Place, that Life, so far as it respects the Body, is, in one Word, the _Circulation_ of the Blood; that is, its Motion in _Conical_ Distractile Vessels from the Heart to the Extreme Parts, and its Return to the Heart again by the same Canals inverted; For ’tis upon this that all Animal Functions, all Sense and Motion Voluntary and Involuntary, do depend; so that the Regularity of this Course is the Measure of Health, or the most perfect Life, as its various Irregularities are the Occasions of Sickness and Diseases, or a beginning Death.

Now all the Animal Operations and Offices which proceed from this Circulation, are the Effects of several Secretions of Liquors of very different Natures out of the same Fluid Mass; It was therefore absolutely necessary that the Blood, before It be distributed to the Organs, should be so comminuted and broken, as that no Cohæsion of its Parts should hinder the Separation of these _Juices_ from It, when it Arrives with a determinate Force at the Orifices of the Secretory Vessels.

This Work is done in Its Passage thro’ the _Lungs_, by the repeated Compression of the Air in those _Bladders_ upon the Arteries, with wonderful Contrivance dispers’d among ’em (160). Herein lies the Use and Necessity of _Respiration_; and the sudden Mischief of Stopping it, in that the whole Mass of Blood being to pass this way, upon a Check here, there presently insues a Stagnation, that is, a Cessation of all Animal Functions, or Death; Which will be the more speedy, if not only no Air is inspired, but a Fluid of a quite different Nature from It succeeds in its Place.

Wherefore it must be observed, that this good Effect of the Air is performed by its _Elasticity_; And that no Fluid whatsoever, that we know besides, is _Elastic_, at least to any considerable Degree, that is, has a faculty of expanding and dilating it self when compressed; No, not _Water_, as near as That is thought to approach to Air in its Nature.

And now as to the present Case, I took notice before that this _Vapour_ is one continued and uninterrupted _Steam_, and that quickly after Its rise it falls down again; that is, that it has little or no mixture of Air with It, or no Elasticity; and is, on the other Hand, very heavy, when forsaken by the Force of _Heat_ that drove it upwards.

So that I make no Question, but that Animals in this Place do instead of Air inspire _Mineral Fumes_, that is, a thin watery Vapour, impregnated with such Particles as do, when united together, compose solid and heavy Masses; which is so far from helping the Course of the Blood thro’ the _Lungs_, that it rather expels the Air out of the _Vesiculæ_, and straitens the Passage of the Blood Vessels, by its too great Gravity; whereupon the _Bladders_ are relaxed and subside, and the Circulation is immediately Interrupted. But if the Animal be in time removed out of this _Steam_, that small Portion of Air which does after every Exspiration remain in the _Vesiculæ_, may be powerful enough to drive out this Noxious Fluid; especially if the Head of the Creature be held downwards, that so its Gravity may forward its Expulsion; or It be thrown into Water, which by assisting, upon the account of its Coldness, the Contraction of the Fibres, promotes the retarded Circle of the Blood; as we every Day experience in a _Deliquium Animi_, or Swooning Fit.

Tho’ if this Stagnation be continued too long, no Art can renew Life, no more than in One perfectly strangled; nor will the _Lake of Agnano_ it self be of any Service; which shews that there is no singular Virtue in That Water beyond any other; nor is it, as some have fondly Imagin’d, a Peculiar Antidote to the Poison of the _Grotta_.

The bad Effects of such _Fumes_ as This will be the more certain, because the inspired Mineral Particles twitch and irritate the Membranes, which are hereupon contracted to that Degree, as not to be able to recover their Tone, and so the Force and Action of the _Lungs_ is quite lost.

It appears from all This not to be at all necessary to make any farther Enquiry into the particular Nature of these Mineral Particles, since they do in this Case act chiefly by their _Gravity_, which is common to ’em all. Tho’ indeed the _Greenish_ Colour of the Earth, together with its _Subacid_ Taste, very much (as _L. di Capoa_ observes) like to that of the _Phlegm_ of _Vitriol_, seem to declare them, if not altogether, yet principally at least, to be _Vitriolick_.

To conclude this Part of our Discourse; I think it a sufficient Confirmation of this Reasoning, that in _Frogs_ kill’d in this _Grotta_, the _Bladders_ of the Lungs (more visible otherwise and distinct in these Creatures than in most others), were found subsided, and quite empty of Air (161). But if any one desires a farther Proof, he may, according to these Principles, make (as _Lionardo di Capoa_ (162) did) an Artificial _Mephitis_; for if _Antimony_, _Bismuth_, or any other such Mineral be finely powdered, and moistened with _Aqua Fortis_, or _Spirit_ of _Nitre_, there will arise a great Heat, and a thick dark Smoak, in which, as in the _Grotta de Cani_, Torches are extinguish’d, and Animals, tho’ but slowly, stifled and kill’d. And this Effect will be more sensible, and equal to the most Violent _Mephites_, if the _Antimony_ or _Marcasite_ be mix’d with _Bitumen_, and the _Spirit_ of _Nitre_, or _Aqua Fortis_, intirely depurated from all its _Phlegm_.

* * * * *

And thus I have shewn how Death may enter at the Nostrils, tho’ nothing properly _Venomous_ be inspired. It were perhaps no difficult Matter to make it appear, how a lesser Degree of this Mischief may produce Effects, tho’ seemingly very different from these now mention’d, yet in reality of the same Pernicious Nature; I mean, how such an alteration of the common Air as renders it in a manner _Mephitical_, that is, increases its _Gravity_, and lessens its _Elasticity_, (which is done by too much Heat, and at the same time too great a Proportion of watery and other grosser Particles mixt with it) may be the Cause of _Epidemic_ Diseases, and, it may be, more especially of those, which by Reason of their untoward Symptoms, are usually call’d _Malignant_.

For it is very Remarkable, that _Hippocrates_ (163) observ’d the Constitution of the Air, which preceded _Pestilential_ Fevers, to be great _Heats_, attended with much _Rain_ and Southern Winds; and _Galen_ (164) takes Notice, that no other than a _moist_ and _hot_ Temperament of the Air brings the _Plague_ it self; and that the Duration of this Constitution is the Measure of the Violence of the Pestilence. _Lucretius_ (165) is of the same Mind, for in his admirable Description of the _Plague_ of _Athens_, These _Diseases_, says He, _either come from the Air, or arise from the Earth_,

――_Ubi_ Putrorem humida _nacta est Intempestivis_ Pluviisq; _&_ Solibus _icta_.

In short, the general _Histories_ of _Epidemic_ Distempers, do almost constantly Confirm thus much, and would have done it more, if the vain Notion of _Occult Venoms_ had not prepossess’d the Minds of Authors, and made Them regardless of the manifest Causes.

And this is notorious enough in those Countries where _Malignant_ Diseases are most rife; Thus it is a very common Observation in the _East-Indies_, that during the dry Heats the Season is Healthful, but when the Rains fall immediately upon the Hot Weather, then _untoward Fevers_ begin to threaten.

The same is observ’d in _Africa_; for (as _Joan_, _Leo_ (166) relates) if _Showers_ fall there during the Sultry _Heats_ of _July_ and _August_, the _Plague_ and Pestilential Fevers insue thereupon, with which whosoever is infected hardly escapes.

And here I might, by Reflecting on the Use and Necessity of _Respiration_, and the particular manner of performing It, (of which I have hinted something already) and considering withal the true Nature of _Fevers_, easily shew how such a Constitution of the Air, as this is, must necessarily produce such Effects; might run over the _Propositions_ of _Bellini_; which _as_ they do plainly evince _Malignant_ and _Pestilential Fevers_ to be owing to a viscid and tenacious _Lentor_ or Slime, which at first obstructs the Capillary Arteries, and afterwards being dissolved by Heat, Ferments with the Blood, and changes it into a Mass unequally Fluid and Glutinous, and therefore unfit for all the Operations of the Animal OEconomy; _so_ it would be no uneasie Task to prove, that Air at the same time _Hot_ and _Moist_, being less able to comminute and break the Arterial Fluid in the _Lungs_ than is necessary, in order to prepare it for Secretions, it is no wonder, if when the Blood passing thro’ the Capillary Vessels arrives at the Secretory Organs, the Cohæsion of its Parts not being sufficiently removed, instead of deriving several Juices out of it into the Glands, it leaves its most Glutinous and Viscid Parts sticking about the Orifices of these Vessels; which tho’ they may at first be wash’d away by the repeated Impulses of the succeeding Blood, yet the Cause continuing, and these Strokes growing still Weaker and Weaker, (from a lesser quantity of Spirits being separated, and hence a more languid Contraction of the Heart) These Obstructions are increas’d to that Degree as not to be remov’d, till by the Violent Agitation of a greater Heat, this _Slimy Mucus_ is thrown into the Blood again, and there in the Nature of a _Ferment_ so disturbs its _Mixture_, and changes its _Compages_, as to make it a Fluid of quite different Properties, that is, altogether unfit for the same Functions or Offices.

This Effect will be the more certain, because a damp Air upon the surface of the Body checks insensible Perspiration, so that a great quantity of this being detained, the Obstructions are still greater in the small Tubes; whereas indeed upon the Account of a more than ordinary Heat, this Discharge ought now to be in an increased Proportion.

Such a Disposition of the Blood as this the Ancients call’d _Putrid_; and to speak plainly, it is a Beginning Stagnation, with a Succeeding Heat and Fermentation.

Nor would it be amiss here to take notice, how unjustly some Authors, having quitted the Consideration of _plain Causes_, for _Occult Venoms_ and _Deleterium quid_, have brought in the θεῖον τὶ (_something Divine_) of _Hippocrates_ (167) to favour their fond _Hypothesis_; tho’ His best Interpreter _Galen_, understood by this Expression no such thing as they mean; but on the other Hand, only the _manifest Constitution of the ambient Air_, such as himself has described in his _Aphorisms_ (168), and which is exactly the same with That We have been discoursing of.

And therefore not only does _Minadous_ (169) rightly Remark, that in his whole _Epidemics, Hippocrates_ never once mentions any _Venom_ or Poison as the Cause of _Malignant_ Diseases; But the Divine Old Man himself in another _Treatise_ (170) expresly teaches Us, that _All Maladies do equally, or one as much as another, proceed from the Gods, there being nothing more Divine in this than in that, each acknowledging its own Natural and Manifest Cause_.

But I willingly wave insisting upon these Heads, as well as the Hints which might be taken from this Theory, of some Use perhaps in the Cure of these Distempers; and leave it to our Physicians to judge upon how good Grounds They do, in Cases of this Nature, under the Notion of _Alexipharmics_, give such Medicines as raise a great Heat both in the Stomach and Blood; only praying Them to take Care, least while They are ingaging the Animal Spirits in War with _Malignities_, They do send Treacherous _Auxiliaries_ to the supposed weak _Party_; that is, that they either raise new Tumults and Disorders of worse Consequence than the Original Mischief; or at least, by clogging the Wheels, and throwing Dust upon the Springs of the finest Machine in the Creation, do check and interrupt the Action of Nature (171), when ’tis imploy’d about the most Nice and _Critical_ Work.

Neither can I, tho’ an occasion be fairly offer’d, by any means be induced to intermeddle in the Controversie of those Gentlemen, who by the help of Two Words are made Masters both of Philosophy and Physick; I mean, the Violent Assertors of _Acid_ and _Alkali_. These scanty Principles fall infinitely short of that vast Variety there is in the Works of Nature; However, for Their Sakes who are as yet Advanc’d no farther, I will advise the Contending Parties, (because little good is got by Quarrelling) to Think of an Union, and if They can find no Remedies but out of these Two Tribes, to make Use of such as result from a prudent Mixture of some out of Each. If this _Project_ does not take, to Resolve however on both sides, To Distinguish the differing Times of the same Disease, and know, that _as_, on the one Hand, _Acid_ Medicines are oftentimes as certainly hurtful in the latter End, as they do service in the Beginning of the Fever; _so_, on the other, those which are _Alcalious_ must necessarily for the same Reason do mischief in the first Periods, for which they are profitable in the last Days of the Distemper.

By what Mechanism this comes to pass, They will easily understand, when they have learn’d what Alteration such things as these are do make in the humane Body; nor will it then be a difficult Matter to convince Them, That He is equally a fond Slave to an _Hypothesis_, who because _Acids_ are sometimes of great Service in Fevers, concludes that their Origine is _Alcalious_; as He who knowing that Stagnating and Fermenting Juices do easily turn to _Acidity_, from thence Argues that _Alcalies_ are the only Cure of this Stagnation and Ferment.

But Dr. _Pitcarne_ (172) has abundantly demonstrated the Weakness of These Men’s Reasonings, and the Vanity of such Immechanical Theories.

And here I would put a Period to this Part of the Discourse, were it not that these Distempers being sometimes _Contagious_, and _Contagion_ being justly reputed a real _Poison_, it may be worth the while to examine a little what This is, and wherein it consists; more especially, because some may perhaps be apt to think This to be an Argument of an _Occult Venom_’s being the First and Original Cause.

We are therefore to take Notice, that when a _Fever_ is communicated by way of _Infection_ from one already Diseased, this most commonly happens in the latter End of the Distemper, that is, (as we before discoursed concerning the Hydrophobia) when the Fermenting Blood is throwing off great quantities of its Active Fermentative Particles upon the Glands of the most constant and easie Secretion; such are those in the Surface of the Body, and the Mouth and Stomach; By this means therefore the Liquid of insensible Perspiration, and the Sweat is impregnated with these μιάσματα, and thus the ambient Air becomes fill’d with ’em; so that not only, (as _Bellini_ Argues (173),) may some of these _Effluvia_ insinuate themselves into the Blood of a sound Person thro’ the Pores of the outward Skin, but also in Inspiration thro’ the Membrane of the Lungs; for He has in another Place (174) demonstrated how the Air, or something from It, may this way come to be mix’d with the Arterial Fluid; And thus the like _Ferment_ will be rais’d Here, as was in the Originally Distemper’d Subject.

This may be _One_, but there is perhaps _another_ yet more dangerous manner of _Infection_, and that is, by the Breath of the Diseased taken in by a By-stander, especially in the last Moments, seizing the _Stomach_, and fixing a _Malignity_ There. For it is upon this Score, that Those who are _Infected_ do presently complain of an extreme Pain and _Nausea_ in the upper Orifice of the Stomach; and that all Authors do agree in the admirable Use of _Vomits_ timely given in this Case; These by their Stimulating Force removing the very _Minera_ of the Disease; and likewise that, oftentimes in _Pestilential_ Illnesses, the _Stomach_ when open’d has been found Gangren’d and Mortify’d. This made _Van Helmont_ (175), who had observ’d this Part in one kill’d by a _Plague Infection_, perforated and eroded in several Places, no otherwise than He had seen in one Poison’d by _Arsenick_, conclude, that the Plague for the most Part begins in the Stomach from a coagulated _Tartar_ there.

Herein lies the difference of _Contagion_, from the first Invasion of Malignant Distempers; The Effects of the _One_ are the Cause and Beginning of the _Other_; and therefore it is no wonder, if tho’ the Symptoms in the former are by a gradual Increase wrought up to their height, they do however in the latter, even at the very first, discover their ill Nature and Violence, and, like a reinforc’d Enemy, by surer Strokes make quicker Dispatch. And this also is the Reason of the great Increase of _Funerals_ in Plague Time, in that One Death is thus added to Another.

If it be difficult to explain the particular manner how the _Stomach_ comes to be thus affected, We must not therefore deny Matter of Fact; and may however probably Conjecture, that the last _Breath_ of one Dying of a Malignant Distemper, proves thus pernicious, in that Those fermenting active Particles, which, as we just now observ’d, the Blood discharges upon the Glands of the _Mouth_, _Stomach_, _Lungs_, &c. impregnating the Air in its Passage thro’ these; when the same happens to be immediately inspired by a sound Person, it may easily taint the _Salival_ Juices in the Mouth, which are very Glutinous, and of a fermenting Nature, and therefore susceptible enough of _Contagious Effluvia_, but especially of such as proceed from the same Liquor infected in the Sick Party. Now the _Spittle_ is continually swallow’d down into the Stomach, and so will quickly impress its _Labes_, or ill Quality, on so tender and sensible a Part; that is, will lodge these Corrosive _Salts_, (for such We may suppose the Particles of Infection) in the Secretory Ducts; whereupon the Glands being obstructed, little _Tumors_ are by the Afflux of their Fluid rais’d here and there, which breaking become small _Ulcers_, and produce that dismal Train of Symptoms which we have already related.

And here it may not be amiss to take notice, that all Authors do agree, One great Cause of _Pestilential_ Distempers, especially in Armies and Camps, to be dead Bodies lying expos’d and rotting in the open Air; The Reason of which is plain from what we have been advancing; For Battels being generally fought in the Summer Time, it is no wonder, if the Heat acting upon the unbury’d _Carcasses_, and _Fermenting_ the Juices, draws forth those active Particles, which in great quantities filling the Atmosphere, when they are inspired and let into the Stomach, do affect It after the manner already described.

To illustrate this Matter, I shall relate a remarkable Story told Me by the learned Dr. _Baynard_. The Body of a Malefactor was Hung up in Chains in the Country; after a few Months, in very hot Weather it was Sport and Pastime to some Boys, Playing thereabouts to Swing the Carcass up and down; One more bold than the Rest struck It with his Fist upon the naked Belly, which being outwardly parch’d and dry, and from the falling down of the Humours Swell’d and Tense, was easily burst by the Blow; out gush’d a Water so Corrosive and Fiery, that running down the poor Lad’s Arm, it caus’d a Violent _Excoriation_, and a very hard Matter it was to preserve It from being truly mortified. What this _Serum_ could do upon the outward Skin, the more Volatile Parts of It would, without all doubt, Effect upon the more tender and sensible Membranes of the _Stomach_, if a considerable number of them were fixt there. The Fluids of Humane Bodies being Ranker and more abounding in active Salts than those of other Creatures, which are not continually repaired and nourish’d by the Juices of Animals.

The Way by which _Bad Food_, _ill ripened Fruits_ of the Earth, _&c._ do oftentimes produce _Malignant_ and _Pestilential_ Diseases, is not very different from _That_ by which We have observ’d Unwholesome Airs to be the Cause of the like Effects. For the Juices with which Those do supply the Blood being Corrupted, must necessarily make a Fluid of quite other Properties than what the Animal Œconomy requires, that is, neither Fit for Nutrition, nor for the Secretion of those Liquors which in the several Organs are to be derived from It; whereupon the small _Tubes_ are obstructed by an unequally Glutinous _Slime_; and it is therefore no wonder, if besides the other Symptoms insuing, _Sore Pustules_, _Inflammations_, _Ulcers_, &c. (more common in Fevers from this Cause than in any other,) are raised in the Surface of the Body.

This is the Ground of the common Observation, that a _Famine_ is very often succeeded by a _Pestilence_. And This _Calamity_ generally begins among the Poorer sort of People, whose Diet to be sure is the worst.

The City of _Surat_ in the _East-Indies_ is seldom or never free from the Plague; and yet it is observ’d, that the _English_ who Trade there are in no danger of being Infected thereby. Now the Chief of the Natives in this Place are _Banians_, who neither Eat Flesh, nor Drink Wine, but Live very Poorly upon _Herbs_, _Rice_, _Water_, &c. and most of the Inhabitants do the like, except Foreigners; This Poor Fare, together with the Heat of the Climate, makes them so liable to Malignant Distempers; from the Attacks of which Those who Feed well are more Safe and Secure.

* * * * *

Thus much concerning _Poisonous Exhalations and Airs_, so far as the Consideration of the _Grotta de’ Cani_ has led Us on to enquire into their Effects; for tho’ there may be other Alterations of this same Element, differing in their Nature from this we have insisted upon, and yet equally Pernicious and Hurtful, yet We take no Notice of any of them, in regard that those which are from _Arsenical_, _Mercurial_, and the like _Fumes_, are reducible to a foregoing _Essay_; and those which are owing to a Change of the known Properties of the Air, may be easily explain’d by what has been already delivered in _This_. I shall therefore rather chuse to make some Remarks on the Mischief of another _Fluid_, which _as_ It is the next in use to This we have been treating of, _so_ the bad Qualities of it, when it comes to be altered, must necessarily be almost equally Fatal and Dangerous.

I mean _Water_, which is of so constant Service, not only for our Drinks, but also in preparing of our Flesh and Bread, that it may justly be said to be the _Vehicle_ of all our Nourishment; so that whenever this happens to put on other Properties than are necessary to fit it for this Purpose, it is no wonder if in its Passage thro’ the Body these do make suitable Impressions there.

Thus at _Paris_ (176), where the Water of the River _Seine_ is so full of Stony Corpuscles, that even the Pipes through which it is carried, in time are incrusted and stopt up by ’em, The Inhabitants are more Subject to the _Stone_ in the Bladder than in most other Cities. The same I observed in the _Baths_ of _Abano_, a few Miles from _Padua_, to that Degree, that it is necessary very frequently to clear the Wheel of a Mill driven by the Current of these Springs, from the great quantity of _petrify’d_ Matter with which it is from time to time incumbered.

In like manner, let the gross Particles with which the _Water_ is saturated be of any other Nature, _Metallick_, _Salts_, &c. these, according to their various Gravity, the Capacity of Canals, and such like Circumstances, will, when they come to circulate in the Animal Body, be by the Laws of Motion deposited in one Part or other. So those Mineral Bodies, and Nitrous Salts, which abound in the Snowy Waters of the _Alps_, do so certainly Stuff and Inlarge the Glands of the Throat in Those who Drink ’em, that scarce any who live there are exempted from this Inconvenience (177).

For this Reason, the Choice of _Water_ for Drink among the Ancients was by Weight, the lightest being preferr’d, as, most free from all Heterogeneous Bodies.

The Case therefore of _Poisonous Springs_ is, their having Corrosive Corpuscles mixt with their Water, which cannot fail when forsaken in the Canals of the Body of their Vehicle, to do the same mischief as they would if taken by themselves undiluted; only with this difference, that they may in this form be carried sometimes farther into the Animal Œconomy, and so having pass’d the _Primæ Viæ_, discover their Malignity in some of the inmost Recesses. Thus the _Fons Ruber_ in _Æthiopia_, mention’d by _Pliny_ (178), about which abundance of native _Minium_ or _Cinnabar_ was found, shew’d its ill Effects chiefly on the Brain; and therefore _Ovid_ (179) says of it,

――_Si quis Faucibus hausit
Aut Furit aut patitur mirum gravitate Soporem._

We shall not need then to inlarge on this Matter, since any of the foremention’d _Mineral Poisons_ may thus impart their deadly quality to Waters; and accordingly there are Instances of _Arsenical_, _Mercurial_, &c. Fountains, of which the Histories may be seen in the Collections of the Learned _Baccius_ (180). And one very remarkable in the _Philosophical Transactions_ (181).

But as We before took Notice concerning _Airs_, so it may be worth the while to observe of _Waters_; that there are some Alterations of them, which tho’ not properly _Poisonous_, yet are of so great Consequence in their Effects, that they may very well deserve to be regarded.

This I shall do with respect to a great Abuse, committed in this kind about the City; and that is, In the chusing of stagnating impure _Well-Water_ for the _Brewing_ of _Beer_, and making other Drinks. Such a Fluid indeed has oftentimes a greater Force and Aptness to extract the Tincture out of _Malt_, than is to be had in the more innocent and soft Liquor of Rivers; but for this very Reason it ought not, unless upon meer Necessity, to be made use of; this quality being owing to the _Mineral_ Particles and _Aluminous_ Salts with which it is impregnated.

A late _Author_ (182) by searching into the first Accounts of the Distemper we call the _Scurvy_, describ’d by _Pliny_ (183) and _Strabo_ (184), under the promiscuous Names of _Stomacace_ and _Scelotyrbe_; and examining the Authentick Histories of It in later Years, made by the most observing Physicians in those Countries where it was unhappily revived, as _Olaus Magnus_, _Balduinus Ronseus_, _J. Wierus_, _Solomon Albertus_, &c. finds that the Origine of It was in all times and places charged upon the use of unwholesome stagnating _Waters_. Then by comparing together the _Clayie Strata_ of the Earth about the Cities of _London_, _Paris_, and _Amsterdam_, He shews that where the Water is worst, there this Malady is most rife. So that He has put it out of all doubt, that most of the perplex’d and complicated Symptoms which are ranged under this one general Name, if they do not entirely owe their Birth to the Malignity of this Element, do however acknowledge it to be their main and principal Cause.

And indeed _Hippocrates_ himself, as He has very plainly decipher’d this Disease (185), by the Title of σπλῆνες μέγαλοι, or _great Milts_; so he does very particularly in another _Treatise_ (186), take notice, that Drinking of _Stagnating Well-Waters_ must necessarily induce an ill Disposition both of the _Milt_ and Belly.