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Wion of ephm into a frog's ftomach, and the circulation of the blood of the animal being examined by a microfcope, no alte-l ration was perceived in the blood, as to its confiftence, colour! Of the ferum, magnitude, figure, or colour of the red globules, | but its velocity was furprizingly diminifned. In about half an hour, the blood regained its common celerity, and the frog its vigour. On giving the creature a fecond dofe, the blood rriov- 'ed flower than it did the firft time, and its velocity gradually decreafiii£, ftagnated firft in the fmaller, then in the larger vef- fels, and" in a quarter of an hour the frog expired. It is re- marka'ile, that, notwithstanding the diminution of the velo- city of the blood, the pulfe was not lefs frequent, and that even when the circulation ft opt in the foot, the pulfe remain- ed vifible by an undulatory motion. On opening the frog, its ftomach was found full of a clear mucus, tinged with the opium, and every thing alfo feemed perfectly natural. This experiment was "repeated feveral times, with the fame appear- ances.
A dog being killed by an injeaion of a folution of opium into his crural vein, on opening his thorax, the lungs were found found, but very fmall, and white* without any blood in them. The heart was big, and all its great vefTels diftended with blood ; but nothing preternatural was obferved in the brain or abdomen.
Opium, externally applied, is difcutient, anodyne, and fopori- ferous, and has almoft the fame effects as when taken in- wardly ; but, that it can make any part infenfible of pain is not evident. Wedelius declares he never could obferve any fuch effects. One inconvenience following the immoderate appli- cation of opium, mandragora, and hyofciamus for pains of the eyes, taken notice of by Galen, is the mydriafis, or a preter- natural dilatation of the pupils. Mr. Ray gives a notable in ftance of this kind, arifing from the application of a leaf of the deadly night-fhade to a cancerous ulcer a little below the eye. The uvea, in a night's time, entirely loft its mufcular force. and was fo relaxed, that the pupil, in the cleareft light, re- mained four times bigger than that of the other eye. Opium rather coagulates, than attenuates the blood. See Dr. Friend's Emmenolog. cap. 14. This favours what is affirm ed by fome authors, that the blood has been found congealed, or frozen, as they exprefs it, about the heart of thofe who have been killed by opium. See Wedel. Opiolog. 1. i.§.i.c. 5. Ufe makes the quantity of opium fafe, and even beneficial, which would otherwife prove poifonous. Daily experience confirms this ; and they who habituate themfelves to opium. find it as neceflary as fpirituous liquors to tipplers. A few grains will deftroy a perfon unaccuitomed to it, but fome dif- orders, as madnefs, enervate its force. Among the Eaftern nations, a dram of opium is but a moderate dofe. Garcias mentions one who took ten drams every day, and tho' fhe appeared ftupid and fleepy, yet fhe difputed very readily and learnedly on any fubject. It is remarkable that, notwith- standing this exceffive ufe of opium, the Turks are generally long liv'd, if we credit Bellonius, lib. 3. obf ii, 15. The action of opium is very analogous to that of wine or vinous fpirits; the good and ill effects of both differ little. See Wedelius in his Opidogia, and Geoffrey's materia medica. Platerus affirms that wine is narcotic, and Sydenham that opium is the moft excellent cordial in nature. The virtues of opium, internally taken, depend chiefly on its action on the ftomach. There are many inftances of terrible fymptoms, and death itfelf caufed by narcotics, before they went out of the ftomach, and without inflaming it, or caufin. any vifible change in it, far lefs vitiating the mafs of blood and alfo of the fame fymptoms being removed, and death prevented by vomiting. Dr. Alfion is alfo of opinion ; imo. That the anodyne and hypnotic virtues of opivm do not di pend on its action on the brain or on the blood, sdo. That it affects firft and principally the nerves to which it is ap. plied; next fuch as 'more immediately communicate with them ; then thofe which ferve for fenfation and voluntary motion; and laft of all, by confent the whole nervous iyftem. 3U0. That this impreffion on the nerves differently affects the fenforium commune and the mind according to its degree, and the nature and function of the nerves primarily acted upon.. 4to. That the primary or firft obfcrvable effect ©f the mechanical impreffion of the narcotic part of opium on the nerves, is the relaxation of their fibres. Now as this relaxation of the nerves, and confequently of the moving fibres, demonftrates opium to be more^than a palliative re- medy in a great many difeafes; fo it is not difficult by it to account for its bad as well as good effects. For by relaxing to a certain degree, it may prove anodyne, cordial, diaphoretic, hypnotic, &c. or caufe ft-ignations, deliriums, lethargies, apoplexies, and death.
It does not appear that opium rarefies the blood, or that the operation of this medicine depends on fuch a rarefaction. If it were, it feems likely that bleeding might be a remedy for the fymptoms occafioned by the abufe of opium ; but fome authors affirm that venefection is mortal even the day after a narcotic has been taken. See Dr. Alfton, loc. cit. We have an account in the Memoirs of the Academy of Sci- ences at Paris, of the death of a young man at Cairo, from his
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being decoyed into taking a very large dofe of this medicine. Among a number of young people in that city, who frequent- ly drank together, there was one who always boafted of his fuperior power to bear a large quantity of liquor, and his com- panions, determined to get the better of him for once, diffol- ved, without his knowing of it, a dram of liquor in the liquor he was to drink ; the confequence was, that, inftead of falling afleep, as they expected he would, he fell into violent deliri- ums, and afterwards into a profound and dead fleep. The next morning his comrades went to fee him, and triumph in their victory, but found him dying, looking livid, without pulfe, and with his mouth clofed. They fent for afliftance, but in vain. After the death of the perfon, the body, arms, and thighs, became covered with livid tumors as big as the head of a young child, and thefe emitted an intolerable (tench, almoft as foon as the corpfe was cold. There is one very fingular accident in regard to this cafe, which is, that this ftench allured all the cats from the neighbouring houfes* who came with great eagernefs, and were hardly prevented from devouring the body.
Dr. Smyth, while at Smyrna, took pains to obferve, what the dofes of opium taken by the Turks, in general, were. He foithd that three drams in a day was a common quantity a- mong the larger takers of it, but that they could take fix drams a day without mifchief. A Turk eat this quantity before him, three drams in the morning, and three in the evening, with no other effect than its giving him great checrfulnefs. But the taking it thus habitually greatly impairs the conftitution; the perfons who accuftom themfelves to it, can by no means live without it, and are feeble and weak ; their legs are ufually thin, and their gums eaten away, fo that the teeth (tand bare to the roots ; they are often alfo of a yellow complexion, and look much older than they really are. The Turkifh meffen- gers, when fent upon bufmefs of hafte, always carry opium with them, and take largely of it when tired ; they fay it im- mediately gives them ftrength and fpirits to proceed, taken with proper precaution, Phil. Tranf. N°. 223. When opium affects the head, or lungs, by its volatile ^ethereal oil, or fpirit, acids, efpecially foflile acids, are the proper cor- rectors. And, when it produces ficknefs, naufeas, vomitings, fpafms, flatulent colic pains, and fuch like fymptoms, by the action of its ponderous, Stimulating, and adhefive oil, the warmeft alexipharmics muft be ufed. Morgan, Mecan. Prac. Phyf. p. 271.
Opium given too foon, to ftop the operation of emetics, has been known to produce dangerous effects. See Medic, Eft". EJinb. Vol. 4. Art. 6. or its Abridgment, Vol. i.p. 160. The refinous part of opium being noxious in Mr. Godfrey's opinion, he propofes to make liquid laudanum, by digefting an ounce and a quarter of opium, in half a pint of dlftilled wa- ' ter twenty-four hours, making the veffel frequently ; then fil- t res it, and adds three ounces of fpirit of wine ;' after which, the other ingredients may be added at pleafure. Mifc. vere util. p. <;o.. Opium Cyrtmiacum, in the materia medica, a name given by fome of the w iters of the middle ages to aJJ'a f^iida. This was the jcordolafaron of the Greek writers of thofe times, and was called Cyreniacum from the place whence it was principal- ly brought. Avifenna tells us, that, in his time, it was brought principally from Kirvan, and that is Cyrene. OPUTODROMI, 03**4^,, amoi.gthe Greeks, a defignation given to thofe who run in armour, at the Olympic, and other games. Potter, Archxol. Gra?c 1.2. c. 21. T. 1. p. 442. The word comes from the Greek wthmi, armour, and ^o^©- a race. OPOBALSAMUM, (CycL) in the materia medica, a name given by fome authors to the true balfamuni judaiacum, or balm cfGi'ead. Dak, Pharm. p. 282. OPOPIA, a name given by fome anatomical writers to the bone*
which form the receptacle of the eyes. Or"ORICE, a name given by the antients to a medicine com- pofed of the autumnal fruits, and extolled for its great virtues againft weakneffes of the ftomach and dyfenterics. It was compofed of five quinces with their feeds, as many pomegranates, a pint of fervices, a pint of Syrian fumach, and half an ounce of faffron ; all thefe were put together into a gallon of muff, and boiled over a very gentle fire to the con- fiftence of honey, with great care to avoid burning. Vid. James Med. Diet, in voc. & Pliny, 1. 24. c. 14. OPOS, a word ufed by the old medica! writers, to exprefs the juices of plants, whether flowing fpontaneoufly, or by means. of incifions. It is ufed by Hippocn;u-s to exprefs the juice of filphium, which was called fimply the juice, by way of emi- nence, as we call the quinquina bark fimply the bark. Others have made it fignify the juice of the fig-tree, and the capnfi- cus, which they had in frequent ufe to curdle their milk. OPOSSUM, or Possum, in zoology, the name of a vevy re- markable American animal, defcribed by various authors, un- der the names of mantacaca, ca'igoi, ropoza, carcgwa, 'ruraiu- ma, tlaquaizin, farigoi, and femivulpa .
It is a creature of the flze of a large cat. Its head is fhaped like that of the fox; its nofe fharp, and its upper jaw longer than the under; its teeth are fmaJJ, but like thofe of the lox
and,
