A B S 



to mention tlie noxious vapours applied to them by means 



of coiitagiouo ditordurs. 



il. Uf irregular allion in the rJforleut veffils. 

 The in. lability or co!itrnii\ik" powt-r of the abiorbents 

 may be prcternauually wcakcntd ; and in that cale, pru- 

 bably, theie will be an acu-iimulalion of the ftcrcU-d fluids 

 in oiif or moiC oi the different natural cavities or iuterlllces 

 cf the body ; for, unlels the adioii of the ahforbents keep 

 pace Witli that cf the exhaknt or fecretinj^ arteries, the na- 

 tural equiLbnuni mull inevitably be dellroyed. Thus it 

 1 a ipenti ui dropiies : either the arteries dcpolit a larger 

 qua.itily ot ferum than can be earned off by the natural 

 power Oi the abioi bents ; or, the latter are detLClive in their 

 action, and cannot take up tiieir ulual proportion of fluid. 

 The different caules and i-emedies ol diminiihed or increafed 

 aftion in this fyllem of velTels is, therefore, an important 

 objeft of euquiry. 



111. ^aijiile chim^cs iniheJlriiBitre of a!j'.rlen!s. 

 Anatomills have taught us to look for various alterations 

 in the itructure of abloibent vefTels and glands, under par- 

 ticular circumllances of difeafe. The diameter of theie 

 valcular bodies is otten entirely obliterated bv external com- 

 preilion and other caufes. They maybe ruptured, wounded, 

 lacerated, or eroded. They may be thickened in their 

 coatb, or rendered unlit for uie by exceiTive iafl.uumation and 

 fuppuration. 



it would be entering into a verv wide field of enqu ry, to 

 coiiiKl,.r what changes the abforbcnt glands and lymphatics 

 undergo in conicquence of tlie abforption of morbid poifons; 

 fur example, ia cuncer, in fyphllis, in the yaws, in the vario- 

 lous., morOiUoua, and vaccine difeafcs, £:c. Sic. On this 

 lubjeiit, we particularly recommend the perufal of profclTor 

 Soemmernng's DilTertation, De morlis vaforuni ahforletilium 

 corporis humnni, 8vo, 1795 ; Dr. Balllie's vT/.^/'/zV/j^nu/cpy, 2d 

 edition; Maleagni's fplcndid work,Z)f I'lnis Lymptaiicis iMr. 

 ^ Cruiklliank's book on iJjc /liiatr/ni-\i of the alforlin^ •vcjl-ls, 2d 

 edition, 410. ; Adams on Morbiil Poij'oiis ; and the conclud- 

 ing part of Dr. Darwin's Zonnomia, vol. i. 3d edition, 8vo. 

 Connetted with tins fubieft, it may alfo be worth while to 

 perufe a curious original piece, intitied, an E^ay on external Re- 

 K me liei, tuhirem it is coJlJered whether all lb: curable dijlimpcrs 

 ■ iiicicicnt to human bodies, may Tiot be cured by outiV:ird means. By 

 ^ P» Kennedy, Cbir. Med. 8vo. Lo.idon, 1 7 15. Refpeftingthc 

 latter work, the author fays, " there has never, as yet, any 



t" thing been attempted of this kind." Introd. p. 5. 

 Absorbents, or Absorblnt Earths, in Chemijlry, 

 are thole earthy fubftances which are capable of imbibing by 

 capillary attraction a large proportion of water : fuch are 

 magnelia, hme, and clay. It is, however, only when 

 theie bodies are diy and porous, that they exhibit th:s pro- 

 perty ; for certain gems, which are pLire argil, and calcare- 

 ou, fpar, which, chemically fptaking, is the fame with 

 clii Ik, are not in the leaft degree ablorbent. Hence ap- 

 pears the impropriety of this t>.imin chemical nomenclature. 

 Indeed it is at prefeiit almoil difcarded. 



Adsorbents, in the Muttria Mcdira, comprehend thofe 

 m«dicinal fubihmces, w'lich, taken inwardly, or applied 

 externally, are adapted to d;-y up or alj'jrb redundant or 

 acid humours. They are fometimes called driers and 

 fweeteners, and by the Latin writers the word is fynony- 

 mous with imbilentia and faiurantia. TheteiTn has been oc- 

 cafioiially confounded' with alkali, btcaufe alkalis have 

 the effett of ahforbents with refpeft to acids. It is now al- 

 mofl rellncled to certain earth.j, which are dlftir.guifliable 

 from others by their lolubii-ty in acids, and which are 

 fuited to imbibe acids, and at the fame time to dellroy their 

 acid q^uality. In reference to this property, fome bare re- 



A B S 



ferred them to the clafs of Antacids. Of the alfvrhr.ti 

 we may reckon the miner.i) calcareous earths, ascha'k ; the 

 animal calcareou; earths, as crabs-claw.s, oyilir-lhells, cg^- 

 fliells, pearl, coral, and coralline ; and anim.il crtlis, not 

 calcareous, as crabs-eyes and burnt hnrllhonu The obvi- 

 ous and immcdi-.ite virtue of tliefe fiilllanics is to obtund 

 acid humours in the lirll pafl'agcs, and thus to rtlitve the 

 cardlalgic and other coir.i>hiints oceafiomd by tliLin : and 

 they poflefs ditlerent properties, and produce difttrciit 

 eft'eft.^, according to th • materials wlilth they abfoib, and 

 by which they are refifled. The relief thty give is often 

 merely temporaiy, as thty ferve to abforb the acid aftually 

 generated, without corretting the iiidilpofition wlilcli tends 

 to produce it. In fome cafes they are inju' ious, for if there 

 be no acd humours in the ilon.acli a..d intelline':, thefe 

 earthy bodies not being foluble by any other kind of fluid, 

 concrete with the vifcous contents of the floinach, and 

 form with them indigefl ble mafTes, which may be very 

 hurtful. Hence have proceeded indigelHon, lofs of appe- 

 tite, naufea, vomiting, obllruiflions of the bowels, and 

 other diforders. Sometimes they have formed a kind of 

 crufl on the ftomach and inteftincs, which has prevented 

 the feparation of tlie gaftric liquor, and obUnided the paf- 

 fage of the chyle through the orifices of the laAeal vclfeii 

 into the mafs of blood. The taking of an immoderate 

 quantitv of crabs-cycs and other abforbentsfor the heart-bum, 

 has fometimes been attended with fatiJ confequenccs. Ste 

 Phil. Tranf. No. 459. Sect. 2. 



It is obfervcd that ahforbents arc of more general ufe in 

 infancy than in adult age. Young children are more lub- 

 jeiSt to acidities than adult perfons, becaufe their food is 

 chiefly of the vegetable acelcent kind, and produces aci- 

 dities, which are attended witli alarming fymptoms, and 

 produdive of various diforders. When infants, or perfons 

 of mature age, but of a feeble coiifl It ution, indicate com- 

 plaints of this kind by four eruftations, palenefs of the 

 face, and in the cafe of children by the four fmell and green 

 colour of the alvine faces, abfoibent medicines may be very 

 properly adminlftered. The other cordial, alexipharmic, anti- 

 febrile, and funilar virtues afcribed to thefe medicines, feem 

 to be founded on an erroneous theory, which attributes the 

 acute difeafes of adults to a morbific acid ; difeafcs whicii, 

 inilead of being produced, are more fuccefsfully fubducd by 

 acids. The ufe of abforbents, fays Dr. Lewis (Mat. Med. 

 p. 643.), in difi'erent kinds offerers, is ncverthelefs Hill con- 

 tinued, and fometimes perhaps with advantage ; for though 

 the earths of themfelves are apparently rather Injurious than 

 beneficial, yet as acids are often given freely at the fame 

 time, the folution of the earth in the acid may prove a medicine 

 more ferviceable in particular cafes tl'.an the acid unobtunded. 

 Different abforbents have been ftlefted and recommended 

 for particular puqiofcs. If it be the intention to alforb, 

 conllrlnge and ftrcn^then at the fame time, chalk, coral, 

 oyfter or egg fliells, are elleemcd the moft eilicacious abfor- 

 bents; if for rettraining a feminal flux, fome prefer the 

 cuttle-bone; for provoking urine, crabs-cyts ; for promot- 

 ing perfpiratlon, burnt hartfhorn ; and for dilTolving co- 

 agulated blood, cnibs-eyes dillblved in vinegar. But all 

 thefe differences have not yet been fufficieiitly determined 

 by experience, becaufe the earths have rarely been given in 

 a diffolved or foluble Hate. It is moil probable, fays Dr. 

 Lewis, that they all ad, when diflblved, as mild coohng re- 

 ftringents ; for wlien they are given in fubllance, as abfor- 

 bents, in cafes of acidities, they all tend to reftrain fluXes of 

 the bellv.or to bring on coitiventfs ; an effvA which Ihould 

 be regarded in the nle of them. It is, therefore, a uecef- 

 fary caution to drink diluting liquors with them ; and alfo 



t». 



