A system of materia medica and pharmacy [electronic resource] : including translations of the Edinburgh, London, and Dublin pharmacopoeias, in two volumes

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The pretensions of Modern Chemisto, as applicd to Materia Medica, are there re more humhle, but they are also more just. By discovering thoge proximate principies of VC-get les in whicli their active powors reside, and cni ling usto Separate them Dona cach other, or froni other inert Indn ious matter avith whicli they may be nuxed, it allows usto apply them W4th much more a luantage: it determines how far in every casu such operations are uSosul: Whether the principies thus opera ted on are altered by theSe operation, and by What means such alterations, is injuricus, maybe obviated. Similar advantages are obtained hom iis application to the few producis of the animal tangitona that areemployed in medicine ; and those bolonging to the mineraltansdom can be used with much more advantage and disci i mination, wlien their nature has been ascertained by analysis, than when we are test to collect their virtves Dom eXperienCe. By the combinations whicli Chemistio regulates, it fur, nisi es us Mili many remedies Whicli ori e to these combina tions their sole power, and whicli axe equalty active withmany of those assorded by nature. Lasib, it has tau tus the proper methods or administering these substances. Many of them exert a mutuat action, Combine together, Ordecomp0se cach other; and V ero such facts Whicli Chemistry discovers not procisely known, important ori Drs would frequently be conlinitted in their mixture and administration.

The last object in the study of the Materia Medica, thatto Whicli the others are subservient, is thoia' MED IcAL HI8-

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MATERIA MEDICA. TORY, or the investigation of the virtves and uses os remedies. This comprehcnds severat important subjects of inquio. There belongs to it the consideration of the action of these substances on the sysicis in iis healthy state ; since, whcnthis is ascertained, it leads to theiae application to the treat-ment os discase. It may in generat be assi ed, though the principie is not without exception, that substances whicli do not aci sensibJy on the hody in a healthy state, Will notprovo active remedies ; and that, on the contra , eVery Substance M ii ii is capille of producing any imporiant change in the syStem, must be more or less extensively adapted toste removat os morbid affections Mothev subjeet os inqui , Scarceb lcsS I portant, relateSto the mode in v liita remedies act,. and by Whicli they produce theiP pecusar offecis. It is not sussicitat mei ely tohave ascertained by the evidelice of experience tho viriues of certain remedies in certain cases. It is os imporiance, aether, to arrange the Deis thus collected to institute somo compariSOn belwCen remedies possessed of nearly the fame generat power, and So fax as cau be done, to iuvestigato their

modo os operation, with the vicis of exteti ling their applicu-tion, and of administering them illi more precision. Lastly, With regata to what may be inore strictly termedihe medicinal po vers of remedies, there are a number of Subjects of consideration M. importance. It is ueceSsary to talaenotice of the applications for which cuch individual ari ictois distinguishod ; the fornis of disea se to whicli it is adapted ;the circumstances that may insuetice iis operation, or in certain cases render iis exhibition doubi sui or impropex; the cautions necessury in iis usu ; the dose in Whicli it is fven ;the usual and paroper forins os exhibition ; und the effecis oLmo combinations of remedies u4th cach Other. These obsexvatious potat out the subjecis to whicli ille at-

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tention is principalty to be directed in the study os the ar-1icles of the Materia Medica. Very disserent systems havo been solio via, according to

perior to the Othors, and sti e possesscd os imito ted adv-tages, ne in Whicli the classification is lauuded on the natural distinctions of the substances aizaugia, the other iuu hicli it resis on thuir medicines potvers. The lalter classiscation appears more systematic, Anil more conformabie to the object of tho study itself, than any other. These substances are subjects of inqui , menely as possessed os certain medicinal properties: they ought to be classed, aheresere, it might be concluded, on principies conformabie tothis : and by lamassing the classiscation on this basis, Someimportant advant es are obtainod; ive are en led is placet0gether the remedies xx hicli aere possessed os similar virtves,to dolivor tho theory of their operation, to compare thepo vers of the individual substances arranged under the class; and by a referetice to this gen aliZation, to poliat out more distinctly their defaeces os activi ty, arul the peculiarities whicli may aettonit the operation Os each.

The principat difficulty whicli attends it, is one arising

ol this kind, and are employed in medicine to oblata this di-

ei Sity Oi effeci, ille samo substance frequently requires tobe considered under disserent classos, and under each iis liis-tory is incomplo c. It may be capsile of actinia sor example, M an emetic, as a cathartic, and as a diuretic : did wo

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MATERIA MEDICA.know prccisely the primary operation of it, ence these ensecis arise, this miglit serve as the basis of iis classification ;but this heing unknown, and the classification being esta-blished on these secondary operations, it must necessarib buplaced under each of these classes, and under each iis histoWis imperisci, as it must he limited to the operation whichives the character of the class Oder Whicli it is arranged. In a Courge of lectures this is inconvenient; the histo os many important articles of the Materia Medica bcingplaced under disserent divisions, frequently remote frona cachother. But in a treatise, to the disserent paris of whicli itis easy to reser, it is of less importauce, and is more thincompensated sor by the other advantages of whicli this method of classification is possessed. And when the meriis of two modes of classification are so nearly balanced, it is evenos importance to exhibit the subjecis comae ted with themunder the potnts of vlew whicli euch mode more peculiarly visords. It is this classification, ther ore, whicli I have sol-lowed in the present Work

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ERATIONS OF MEDICINES.

THE advantages of an arrangement of the articles of the M teria Medica, unded on their medicinat operations, I havestaled under the preceding observations ; and in endeavOu ing to coibit this branch of medicine, Strictly aS a Science, it is that mido tedly whicli ought to be solio ed. The dissiculty of constructing such an areangement, has at the Eame time always been experienced. No subject is involvedin greater obscv ity, thau What relates to the action os subiastances on the siriog system. Thela effecis are not alwayseasily appreciated with accuracy, especialty in a state os disease, and our knowledge of the laws of their action is extremely imperfeci. When we attempt, there re, to classiliem according to these actions, we caii SCarcely forna an ar-rangement strictly just alid systematic, but are forced to admit of sonte deviations, and to be guided not unirequently by imperfeci analogieS. The dissiculty Os constructing a classification os medicines Dona their operations, will bo apparent froin the lallure evenos Cullen, when he attempted iis execution; DP there can

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GENERAL VIEW OF THEn principies nearly altogether false. The soll0wina xliibiis this classification. Stimulantia.

Simplicia.

QAcrimoniam corrigentia. In genere. Demulcentis.

Νοw, Without examining it minutely, it may bo rem ked, that the basis of this classification, ille assumption that sonae medicines aci exclusively on the suids of the body, is incor-

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of the boh, giving it density or tone, but by their operationou the vital po vers of the system. bor Cin the effects of astringenis he ascribed enti Puly to theiae corrugating quality. In this avrangement too, are placuit Classes os, medicines ich have mob ly no existunce, the action ascribtid tostem betag merely hypotheticat. Me may be alloived toquestio A the cxistence of attenuanis und inspissanis, medita ciues ivllicli render the sui is of tho both more thin, or whicli produce the opposite effeci. Nor is thure any rcason to heliove in the reality of antis lics. The process of putresac-- tion probably never talaes place in the living body ; and is it did, we know of no medicines by whicli it could bo retarded

In the system os Brown, advanced in opposition to thatos Cullen, more just vieri s ivere unquestion ly given of the relations os extemia agenis to the living systona, and of thelari s regulating tlieir action. Tlio oporations os medicines, hori everi are even in this system impersectly explained,

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is exciting to action ei er the generat system, the particular organs on whicli they operate; aud to dister fim cachother in litile more than in tho degrest in whicli they exerilliis stimulating potver. They have, further than this, nospecilio properties, but are adapted to the removat os moria bid affections, by producing excitument, partici oz generat, ivitii certain degrces of rapidity or force. , This proposition is far stom being just, at least in an

limited senSe. Medicines, and even externat agentS in gene-xat, unquestion ly differ, not oiij in degree, but in Lind of

action. Every substance applied to the organs of SOS Hves a disserent sensation, itot reserritae to the mere soroe o the impression, hut whicli must be attributed to sume essenties varieties in the modes of action of the agenis themselves

Every organ is excited to iis usual or healthy actiou on byiis appropriate stimulant. It is the Same Mili regata. to medicines, or differences in the kind of action they exert arenot less conspicuous. Opium and mercury both excite thoactions of the system, and So fax they agi m in thoir generaloperation. Lut the ultimate essecis they produce are extremeb dissimilar, nor stom either os them can v e, by any Variation os dose, or mode os administration, obtain those

Stiis the principies of this system approach to the truth, and appear most consormabie to the latus udiich regulate theanimal economy, anil, with some modifications, they may beapplied 50 to inbrd a more satisfactoo vlew of the opera-

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OPERATIONS OF MEDICINES.

tions os medicines, and semidations sor arranging them undor disserent claSSeS. Is we attend to the generQ operation os medicines, esiuit, that it is usuntly that os exciting to stetion, either thegenerat system' or particular organs. This is the primat effeci; and to express the aguncy of the substance producingit, the term os stimulant operation may be employed. And, accord g to the Lind and degree of this, disserent effecisV ill he produced, tho discrimination of hich may an ord severat important distinctions. Thus, of those stimulants whicli nct on ille generat system, the operation is extremely disterent with regarit to diffusibili ty and permanetace. Some are highly diffusibie in their ac tion, or, soon aster they have been received into the stomach, they produce increased Vimur, Whicli is immediateb conspicuous in the force of the circulation, the nerVOus System, ortho different functions of the hody ; While, With regni d toothers, the fame generat effect is produced more Siori y, Indis scarceb perceptibie but froni their repented or continuod administration. Those Whi gli are diffusibie are at the samo time generalb transient in thela operation ; while iliose whichproduce excitement more Sio y, Me generalty more perin noni. And by both diversities of action, it is obviolis their operation inust be productive of Very disserent effecis: tholito excitement produced by the one is generalty immediates3 foliori ed by proportiones languor; the gradunt excitement fronatho other being reduced more flowly, they OCcaSion no Suchsudden changes, but are sillud to produce more lasting esse is. Tliese varieties of action servo, accor lingly, to explain thedissereticus in the povir of some of Oiu' mOSt important medicines, and they aiford the distinctiou of two principat classes, Narcotics md Tonios ; the one, So sar iis thoir action is im-

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transient, the others .uo v and permanent.

Othor important differcnce among stimulanta is derived froni tho action os sonio buing generat with regxrd to the system, i ite that of others is more peculiarly directed topateticular organs. The effect with rogarit to cither is noteasib explained ; but the fact is certain, that Somo substan-CeS, as Soon as they are received lato the stomach, not on produce on it a stimulant effeci, but extend this to the generat system ; whilo there are Others whicli, without any Vc evident action on the stomach, and stili Iess without any generat action, excite particular organs: Some, kr eXample, stimulatuig the intestinat canat, Others exciting the action of the secreting vesseis of the kidneys, and others opera ting onthe exhalent vesseis of the skiu. These afford the distinctions os cath lics, diuretics, alid diaphoreties, and there areother classes se ded on similar locat operations. With this

Iocat action, many Substances exert, at the Same time, moreor tess of a generat operation, by whlah the individuals of a class become capsile of producing peculiar effecis, and many of them, by peculiari ty of administration, aci specificatly onmore than one part Onthe System, by whicli their e cis arestili more diversified. 'aen medicines are thus detormined to particular paxis, they are ei ther directly conveyed, by beii,g received into theblood, or their action is communicated indirectb froin the Stomach, by the medium of the nervolis system ; and in both

M ys important locat effecis are produce l. Thus, there are many substances Whicli appear to be capillo of heing so sar assimilatcd with the sood, as to clator into the composition of the chyle, and are received into the circulating mass. ueing brought, in the coita Se of the circulation, to particular organs, thes osten excite in them pe-