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 MED

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MED

and Events, fecm'd to have almoft brought the Art to its Perfection.

jitpfocrates t who was Cotemporary with Democritfis, and perfectly acquainted with every thing hitherto laid down, and bcfides, fumifh'd with a great number of Obfcrva- tions of his own, collecting into one all that was valuable and ufeful ; compiled a Body of Greek Medicine ; and was the firS who deferv'd the Title of a true Phyfician : for being a MaSer of the %ymad<t. Experience, as well as of Analogy and Reafon, and withal well verfed in a pure Philofophy ; he, firit, made Phyfic rational ; and laid the Foundation of the dogmatical Medicine, which has ever fince obtain'd. See Dogmatical, Theoretical, &c.

What Hippocrates had done, cominu'd a long time fa- cred and unalter'd, and was the (landing Practice of many Ages ; at length Cretans the Cappadocian digeSed it into a more orderly Body : whence, in various Places, at va- rious Times, and by various Hands, particularly the Alex- andrian School, it was further alter'd and improv'd ; till at length it came to the hands of Claud. Galen ; who col- lecting the fcatter'd Parts, digeSing thofe that were con- fus'd, and explaining every thing by the rigid Doctrines of the Peripatetics, did both a great deal of fervice, and a great deal of mifchief, to the noble Art ; he being the firft who introduced the Doctrine of the Elements, the Cardinal Qualities, and their Degrees, the four Humours, £5?c. into Medicine: and on thefe he made the whole Art to depend. See Temperament, Humour, Quality, g r e f, £> c.

After the fixth Century, the Arts were not only extin- guiflfd, but almoft all Memory of them loft, till the ninth; from which, to the thirteenth, Medicine was vigorously cul- tivated by the Arabs in AJia t Africa, and Spain : who ap- plying themfelves particularly to the Srudy of the Materia Medica, and its Preparations, and to the Operations of Chirurgery, render'd both more juft and more copious at the fame time. And yet Galc7t > s Errors became now more predominant than ever.

At length, however, they were purged out and ex- ploded by two different Means ; principally indeed by the Rettoration of the pureDifci'pline of Hippocrates in France j and then alfo by the Experiments and Difcoveries of Chy- mifts and Anatomifts : till at length the immortal Harvey overturning, by his Demonstrations, the whole Theory of the Antients, laid a new and certain Bafis of the Science. Since his Time, Medicine is become free from the Tyranny of any Sect, and is improv'd by the fure Difcoveries in Anatomy, Chymiftry, Phyfics, Botany, Mechanics, £5?r.

Hence it appears, that the Art originally confiSed fole- ly in the faithful Collection of Observations^ and that a long time after, they began to enquire, and difpute, and form Theories: the firS part has ever continued the fame ; but the latter always mutable. For the feveral Sects that have arofe among Pbyficians, fee Emperk, Dog-

MATICj t$C.

Medicine is divided into five principal Branches. The firS considers the Human Body, its Parts and Fa- bric, its Life and Health, and the Effects following from them j and this U call'd Phyfiolo^y, the Animal Oeconomy, or VoBrme of the Ufe of the Parts; and its Objects, now enumerated, are call'd Res Naturales, or Things according to Nature. See Physiology, Natural Things, £5?c.

The fecor.d Branch confiders the Difeafes of the Hu- man Body, their Differences, Caufes, and Effects; and is call'd Pathology, as it confiders the Difeafes ; JEtiology^ as it enquires into their Caufes; Nofology, when it exa- mines their Differences ; and laSly, Symptomatology, when it explains their Effects. The Objects of this Part are call'd Res prater Naturales, or beyond Nature. See Pa- thology, &c.

The third Branch confiders the Signs or Symptoms, and how to apply them to TJfe ; fo as to judge both in a found, and a difeafed Body, what, which, is, will be, the Degree, Order, Effect, of the Health, or the Difeafe : This is call'd Semeiotica. Irs Objects are Things both Na- tural, Non-natural, and Prater-natural. See Semeiotica.

The fourth Branch confiders the Remedies, and their Ufe, whereby Life may be preferv'd; whence 'tis call'd Jiygeine. Jts Objects are what we Srictly call Non- natmals. Sec Hygeine and Non-Naturals.

LaSly, The fifth fumifhes the Materia Medica, its Pre- parations, 'and Manner of Exhibition, fo as to reftore Health, and remove Difeafes ; and is call'd Tberapeutica, comprehending the DUtetica^ Pharmacetttica, Chirurgica, andjetrica. See Di^etetica, Pharmaceutica,Chi- kurgica, and Jetrica.

MEDICINES, or Medicaments, Preparations of any na- tural SubSances, apply'd to a human Body, in order to anfwer fome Intention of Cure. Medicines are dillinguifh'd, with regard to the Manner of Application, into Internal and External. Internal, are thofe taken in at the Mouth : External, or Topical, are thofe apply'd to any particular Part. See ToncA*, &c.

With regard to the different Manner of their Operation, they are diitinguihYd into Evacwnts, AJlringents, and Al- terants, or Specifics. See Evacuants, Specifics, Al- terants.

A general Idea of the Manner wherein Medicines operate on a human Body, may be conceiv'd from what follows.

A few different forts of Particles, varioufly combined, will produce great variety of Fluids ; fome may have one forr, fome two, fome three or more. If we fuppofe only five different forts of Particles in the Blood, and call them a,b, c, d^e, their feveral Combinations, without varying the Proportions in which they are mix'd, will be thefe follow- ing : but whether more or lefs, need not be determin'd. a b : a c : ad: a e : be i bd : b e : cd : c e : de : abc : adc : a bd x abe \ ace : ade : bde : b de : bee : dec: abed : abce : aede ; a bde : be de : abc de : No Theory of Secretion has hitherto been able to give any tolerable Account of the Operation of fuch Medicines, as pro- mote an Evacuation. For if the Humours are equally mix'd with the Blood, that is, if the Blood is in every part of the Body the fame, and its Particles are not more apt to form certain Humours, in fome certain Parts of the Body, than in others ; or if they are not forced, by the Power of fome Medicine, to form fuch Humours; then the Quantities of Humour, feparated in equal Times, will always be as the Velocity of the Blood ; but the Velocity of the Blood is feldom doubled by any Medicine, and never tripled by the moll acute Fever. The Quantity of Hu- mour, however, drawn off by evacuating Medicines, is often twenty times greater than the natural Quantity ; and therefore, upon fuppofition that the Humours are every where equally mix'd with the Blood, the Operation of evacuating Medicines can never be accounted for.

Tho this Argument hath the Strength of a Demonftra- tion, yet there are fome who explain the Operation of purgative, and other evacuating Medicines, by a {Simu- lating Faculty; whereby the iluggifh Juices are not only fore'd out, but the obSructed Canals open'd, and the Motion of the Blood quicken'd. But tho fuch a Power be allow'd, it would remain to be explain'd, why certain Medicines do only Simulate certain Glands? For it is evi- dent, that evacuating Medicines have fome other Power, beficks the fqueezing out flagnant Juices ; becaufe when they are all fqueez'd out, they itill evacuate as much, if they are repeated, as they did before : as is plain, by continuing a Salivation tor many days. Secondly, we cannot lupppfe a that all Bodies have every where, and at all times, Juices Sagnatingj but thefe Medicines constantly produce their. Effects, more or lefs, at all times. Thirdly, if the Vef- fels be fuppnfed to be obstructed, u.n evacuating Medicine could but double theQuantity that was evacuated, before it was taken. Fourthly, if thefe Medicines operate only thefe ways, then in a healthful Body, where there were no Obfiructions, they would have no effect at all. Fifth- ly, if the removing Obstructions were the Caufe of a greater Quantity evacuated, then the Evacuation ifiould Sill continue in a greater degree than before the Obstruc- tion was removed ; whereas, in fact, we conftantly find it lefs, as the Medicine works off. Sixthly, tho a Medicine, by Simulating a Veffel, may quicken the Motion of the Fluid in that Veffel ? yet it can never increafe the Quantity of Fluid running thro ir, in equal Spaces of Time ; beciufe it quickens the Motion of the Fluid, only by contracting the Veffel : and therefore the fafter the Fluid is made to run thro' the Veffel, the lefs Fluid the Orifice of the Veffel admits; and confequently after the Veffel is con- tracted by the Simulating Medicine, the Secretion will be lefs, inSead of being greater. That a Stimulus caufes the part, on which it acts, to contract, is matter of fact ; and that purgative Medicines do Simulate the Bowels; but it may perhaps be likewife faid, they Simulate the Heart and Arteries, and increafe their Force, being they not only quicken, but raife the Pulfe : fo that a greater Quantity of Blood is fent to the Glands of the Guts. This may be granted ; but not that it is the principal Action of pur- gative Medicines ; becaufe that, by the fame Force, a grea- ter Quantity of Blood is fent to all the other Glands of the Body, whofe Fluids are not, however, fenfibly in- creafed ; and the Glands of the InteSines receive a lefs Quantity, in proportion, than any others, becaufe they cannot be fo much dilated by the greater Force of the Blood, as others, which are not fo much Simulated by the Medicine. There are others, v/ho will have evacuating Medicines endued with an attenuating Quality, by which they diffolve all the Cohefions of the Particles of the Blood, and fo fet the feveral Humours at liberty, to pafs thro* their proper Glands : but if thefe Medicines have a power univerfally to diffolve all the Cohefions of the Blood, then every evacuating Medicine would equally and

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