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.