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1 octing aikohol into the stomach of a smali animal, or in uo lucing a sinali quantity of the juice of aconite, Ox of thoessentiat Oil of the bitter almonil diffused in water, or of the
leaves of tobacco, into the rectum, or in a concentraled state
into asi Wound, the ontire loss of voltuitary motion, and totalinsensibility were producod; yet even wheu this state Wasallowed to continue untii est the externat sigiis of apparentdeath were produced, the he i, when expoSed to Vie v, Wasfound contracting with considerable force, and by lassating the lungs and producing artificiat respiration, iis action Couldbe kept up nearly to the natural standard sor a considerable period. It appears, there re, that whil' the nexVOuS VS-tem Was so much assected, the po vers of the circulating System were litile impiared; aud the cessation of the circulation
ultimateb producing death, sarther appears in Such cases toarise principat ly froin the respluation being assected, and attengui ceasing in consequence of this function hemg so muchmore dependent on the insueuce of the nexues. The imui diate essects of narcoties arise, ther ore, Dom affection of the functions os ille brain ; the function os respiration is a lacted in consequence of this, and at imgth ceases, and this OccasionS, Or at lcast accelerates, the falli e of the circulation, whicli produces death. Froni this an important Conclusion fossori s. In the case os insensibility produced by the operation of a dareotic, rus the heari continuos to act, it is possibie, that is the cessation os iis action bo prevented by keeping up xespiration artificialj, xhe assection os the brari may gradually pass Osf, and the functiviis os life be restored. Λ si1 king experiment in illustration of this, is stated by Mr Urodie, in Whicli tho state os total insensibili vas in-l liquod in a rabbit by a di op of the ossenties oti os almondii inseri ed into at wounii; astor sive minutes respiration had
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lise have been extinguished : artificiat veSpiration Was excitiaod, in sis minutos the animal moved and made an ossori tobreathe ; these efforis Uere repented, after Sixteen minutes tho artificiat respiration was discontinued, Sptintancolis xeSpiration being esta lished ; ali the iunctions revived, and in tu ohoura the animal appeared to be perfectly well. In another case the animal recovered froni a state os insensibility, after artificiat respiration had been excited for ne ly three houra. Froni these facis, the preventing the fallure of respiration, and the exciting it is necessa artificiat b, at the fame time Leeping up the proper animal temperature, Would appear to. be important indications in the extreme State os exhaustion occasioned by the operation os a narcotic. I here are somo narcotics whicli appear to operate ivithmore force on the muscular fibro, and whicli directly assecttho heart. The infusion of tobacco . injected into the intestines occasions immediate loss of motion and sensibility, and
the licari, instoad os continuing to contraci, Was , found by AIr Brodie to h ve ceased contracting, and to be distendedwith bicod. The porson os the quas antiar has a similar effeci: but at is singulari the distilled Oil of tobacco does not aci like the infusion, but like other narcoticS. The the y of the operation os narcotica is attended miliconsiderable dissicut , and very different opusiolas have been maintained with rogarit to it. . As they in generat diministi the actions of the system, Whengiven even in a smali dose, it happetita, that froni their exhibition this effect was in generat most obvious, and their Stimulant operation was more rarely observe i. Helice their
primary action Was generalty considered res of a depressingkiud, and they ivere described by authors under the appellation os Sc lativos. The stimulint effecis ulli ch v ere uiso
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observed to ariso Dom their action, vere ascribed lo what was termed the re-action of the system. It WaS Supposta, that there belungs to the animal frame a poWer, ille tendencyos whicli is to resist and obviate the effecis of any thingnoxio . Is such in agent utere applied, this principie Wasbelieved to be roused tuto action, and est the po vers of the
system were excited to throw off the noxious application. On this hypothesis, the action os narcotics was attempted tobe ex alaed by Cullen. Their natural tendenCy was sup- posed to be to depress the po vers of lise ; is seven in a large dose, this Was exerted with effeci, and hence the Symi)tonis of exhaustion ; but, is seven in a sinster dose, the vis
medicatrici, or preServing pDaver, P a S enabled to regist, and by iis resistance occasioned the sympionis of increased actiouthat fissi apphared. These Substances, ther Ore, M Cre Considered as directly sedative, and as indirectly Stimulant. Precisely the reverse of this Vieri ratas advinced by Uro si narcotics heing regarded as stimulanis, sui passing ali othei Ain ille diffusibility and litile durability of their action, indon this principie their inecis ivere explaiuod in the following
It is tho necessary effect os stimulant operation, to produce for a time incremed action ; but as this is attended witha diminution of vitai potver, the eXcilement Soon cenSeS, md diminished action succeeds. These effecis are proportional,
partly to the. absolute sexce of the exciting pou er, and parilyto the rapidib with whicli it operates. Is sufficiently Strong, and is, at the samo time, it he diffusibio and transient in iis operation, the excitcnient it produces is quickb inised to iis highest p0int, and is as quickb hollo aed by proportional , langu0r and diminishod action. Os is the d0se is large, thostimulant effect is su rapid as to he havdly pexceptibio, and hqrice the sedativo or depressing cnecis only applar. I lius
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Is, in investigating this subjeci, wc mereb contrast theSe two theories, litile doubi can rema in of the superiority of the lalter. The sermor is semided on a bypothesis est lish-ed by no evidelice, that a pomer presides ovex the System, Leady to resist every noxio us application ; the lalter is apparently more strictly deduced from the properties of the sub-Stauces whose operation is to he e lainta: for, as it is prov-ed, and indoed admitted, that the stimulant operation result-iug Dona the exhibition os narcotics sollows immediately, and previous to any symptoans os languor and debilio, these ought
strictb to be considered as the consequences of the former. The most extensive analogy too has been traced bet ween theoperation os narcotics, and other substances aikwed to bestimulant, but whicli are less rapid in their action ; as, sorexample, between ardent spirit und optum, though in the onethe stimulant, in the Other the sedative operation is usuallym0re apparent. Anil, lastly, the ad vantage derived froni thecautious achninistration os narcotios in sonae disinses of diminisbed action, is scarcely compatibie with the supposition ortheir cXerting a direct depressing ΡOWer. The principat dissiculi y attending the theoxy, at Ses Domitio faci apparently estublished, that the sedativo po ex olthube Substances is not uiri stys proportional to their Sti-
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mulant speration, but is greatex thun this, and in severat orthem indeed any previores stimulant effect iS eVen Scarcebperceptible. Yot this dissiculty is in somo measure obviatia by the faci, that substances, the stimulating action Os whichis unquest nable, as ardent spirit, is seven in a Very large dos produce depression without any previous perceptibie incre cd action. In like manner, electrici , applied in moderate quantity, stimulates the muscular fibre to contraction ; while, applied in a hiily concentraled state, it instantaneouSU produces total exhaustion of the contractile power. The more forcibb, theae ore, a stimulant Operates, the more rapid doesthe immediate action appear to be produced, and the more quickly to cerae, so as to he followed by the secondary es-
feci ; and with the admission of this principio, may pertrapsbe explained, ou this hypothesis, the faci, that the sed lixe
any probabiliu on their action, may be regarded as generaldiffusibie stimulantS. Tlie hypothesis may also, however, be maintained perhaps, that along with their stimulating operation, they directis exhaust the po vers of life ; and that these two modes of actionare not strictb proportional, but are different in disserent
narcotics. The . est ects of certain cliomicat agentes on the System, as of nitrous oxide, and carburotted hydrogeia, favoux
an hypothesis of this hin d ; tho oue producing hio excite-
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Iations are deficient in precision ; nor cau We do more than State the most generat analogies, without attempting to extend them to any very minuto applications. Thus, in ali thetheories which have been advanced with regard to the operation Os narcotics, the conclusions have been d wn froni thoaction of a fow of the most potversul,-aikohol or Opium. They axe, after ali, imperfectly adapted to these, and a re stili
more deficient when considered in relation to the others. As narcotics are capsile of heing administered, So as to tam Dona their action either Stimulant or sedative effecis,
it is obvious, that they may be emploed as remedies, withtho vlew os producing cither of these. The excituag Oper tion, however, is in generat So transient, that sew of themcan be administered with advant age as stimulanis. Wheugiven with this intentioli, they ara applied in sinali dose frequently repea ted, as thus ille state of excitement is hest Susta ed. More usualty th are ovo with the:vi of
taining that state os diminished action and susceptibility to
impression, Whicli is the more common and more eastly regulated consequence of their operation ; they are then givenin larger doses at more distant intervess. AS Sthnulanis, .ihey are sumetimes employed in various fornas of continued sever, remittent and intermittent severi and numerous dis- eases of debili ty. Αs sedatives, they are. Stili more exte sively used to alleviate or remove spasmodio action, to assaypam and irritation, to induce fleep, and in restrain morbidlyincreased evacuations and secretion S.
There is a peculiarity in the operation of narcotics, that by xcpetition their action on the systoni is duniuished morethan ibat of any other class of medicines, so that, alter haVing been used for sonae time, they require to be given in in- creaSed doses to produce their usual effecis, and quantitie.
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os them have at longin been tineia, whicli at i st would havo destr ed illa. No very satisfactoo explanation has beengivon of this, sor it is not connected with any proportiones reduction of irritability, or any apparent permanent change di in the system ; but the faci is generalty true with respect tothese medicines, and requires to bo attended to in thois ata inistration. D appears too to be more peculiarly the casewith some than with others. It is rem habj sο, sex e ample, With opium, Min iobacco, with hemiock, while it is sciscob to be observed with regata to singlove. The individual narcotics may be arranged parib accordiugio their cheruical relations, and parily according to analogies
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these liquora a produci is obtamed by the process of distillation, whicli, in the diluted state in Whicli it is ut first procured, forins the spiritous liquors os commerce. By repeat-ed distillations, it is procured more pure and concentrat , and then forins what was named Pure Ardent Spirit, or Spi-xit of Mi ne by the older chemisis, ames for ich that os Athohol is substituted in modern chemicat language. This Substance operates On the living system as a litob diffusibio stimulant; in the state os spirituus and vinous Equors, it is e loed ser medicinal purposes ; and in iis pure serm is anisportant pharmaceutic agent. At hol is formed during the process of sermentation; and Dom the changes whicli , occur during that process, weinde our to inser the theory of iis formation. Saccharine matter, in the state in Whicli it exigis in sweet vegetablejuices, Mid secula, whicli has been converted by matting into
Sugar, Or even secula to a certain extent unmalteri are thei substances chlassy susceptibie of this process : the ac dthe ala is not necessary to it; and the water of the fermentia ing liquor Mes not appear to Suffer decomposition. Theseries of changes, whonce the aikohol is s med, must arisetheresere fi Oin the reaction of the elements of the veget te matter, and the new combinations whicli are esta-blished. These elements are carbon, hydrogeia, and Oxygen ;during the fermentation, carbonic acid is formed and diseu-gaged : this must bc derived froni the combination Os po tions of the oXygen and carbon of the saccharine mattor cor orthe fecissa, whicli is of similar composition); and tho al-
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under this poties of vlew, be conSidered as a comp0und os ibo xeniaming elements ; in other W0x is, of the hydrogon os thesugar ivitii iis rema ing carbon and oxygen. This is thotheory of the vinous fermentation, and of the composition os aikoliol inferred by Lavolsier, frona experiments underlahen th the view of investigating this subjeci.
MOre recent researches, hora ever, have Shewn that it is imperfeci. I avolsier had supposed that pure Sacchatine matter ulone is capabie or fermenting, and that the u holechanges Whicli occur during ille process are changes in iis composition. Lut this is not strictb triae. TO excite se mentation in a solution os pure Sugar, a certain quantity of at is named Forment, of which yeast is a variety, is necessa a , and sWcet vegetable juices Suffer it oesy Dom natural ly containing this serment. The agency of this substanco Temesiis to be explained, and this has n0t yet been done in s Satisfacto maniter. It appears to approach to gluten orniumnen in iis nature, and in particular contains nitrogen in iis composition. This nitrogeia, it is Sheum by the experiments of Thenard, disappears during the fermentation, and he has supposed that it enters into the composition of the: ι ouol, while a poriton too of the carbon of the sementcombines With part of the oxygen of the fugar, and contributes to forin the carbonio acid disengaged. The whole os this subjeci, however, requires farther elucidation.
Froin the analysis of aikAbI, it appe s to be a compo dor carbon, hydaeogeia, and oxygen ; helice, in bimiing, it a sordes mereb water aud carbonio acid, and tho quantity of ater produced excee is even the allioliol in v eight. L Voiqier inferred, that it consists of 28. 5 of carbon, p. 8 os hydrogeia, and 63 5 of water, Without any concluSive proos,h0WeVer, that this large quantity of water exisis in it sui sermed, and n0t in part at least in illo state os iis clements.