A I R 



A I R 



iHuflratc tlie mc-dicinHl powers of air, in its clifTcrent combi- 

 irations. T!ie apj>lication of fixtd air, or carbonic acid gas, 

 by means of the fermenting cataplafm, is pretty generally 

 known, in cafes of fetid and cangnenous foies. It has 

 been advantagcoully ufed ;ilfo m malignant ulcers of the 

 nofe, tongue, and m.oiith, as well as in caries of the 

 bones. 



Fixed air is plentifully obtained from a mixture of alka- 

 line or chalky fubftances witii vitriolic acid ; and during the 

 cfFervefcence, applving the gas which is extricated immedi- 

 ately to the morbid part ; or by impregnating water with it, 

 comprcffes may be loaked in the water, and laid frequently 

 over the feat of the d.fesfe. Mr. LoelHer, a German fur- 

 geon, has recommended a particular apparatus for this pur- 

 pofe, which may be eafdy conlhufted , and which he em- 

 ploys for faturatirg water with fixed air, by the mixture of 

 chalk and vitriolic acid, or during the procel's of fermenta- 

 tion. 



When we wifh to apply the air to a cancerous breail, for 

 example, we are to fill a bladder with the air as it rifes from 

 the above mixture. Then introduce a tube, fixed to its 

 crilice, into another bladder, which is to be cut round in 

 fueh a manner that it can be applied like an open bag avouiid 

 the breait, and held dole to it with the hands. When it is 

 faftened below, it mull be untied, fo that the fixed air may 

 pafs out of the firll into the fecond bladder, and find acceis 

 to the ulcei'ated part. In order to facilitate this procefs, 

 a gentle degree of preffure is to be applied to the bladder ; 

 and, as one bladder will not be fuffieient, a number of them 

 fnould be provided in readinefs, and filled for immediate ufe 

 in fuccedion. This operation is to be continued half an 

 hour or longer each time, and repeated twice or thrice a 

 day. 



Mr. AVitftock, who has written a German treatife on this 

 fubjecl, and with extraordinary fuccefs, recommends us to 

 apply the carbonic acid gas, by means of a receiver or air- 

 be!l, conneiSled with a flexible tube or pipe, fiifficiently air- 

 tight ; but as the vitriolic acid produces too ftrong a com- 

 motion, the gas is extricated for fueh purpofes from a mix- 

 ture of fixed alkali and vegetable aicid. 



The medicinal ufe of factitious aii-s is a fubjeft which 

 has been dihgently confidered by Dr. Beddocs, Dr. Thorn- 

 ton, Mr. Hill, Mr. Davy, and fome other gentlemen in 

 England ; but the enquiry is illll in its infancy, and has not 

 been productive of fo mush public benefit as its zealous 

 friends anticipated. Perhaps the attention of medical men 

 to tlie local and external influence of gafeous matters, would 

 better repay them for their trouble. Surgeons arc not ex- 

 tilly agreed, whether the atmofpheric air be hurtful to 

 v.-oands and internal cavities, merely as air, or as it may be 

 cold, hot, moiil:, dr)-, or varioufly modified. We hope 

 tbefe fuperficial hints will ferve to excite the attention of 

 profefiional gentlemen to this branch of the healing art. It 

 tikewife deferves further enquiry, whether the injeflion 

 of fluids into the urinary bladder, impregnated with fixed 

 air, &c. &c. be fo efficacious, in calculous cafes, as fome 

 perfons h::ve pretended. 



From obfervations on bleeding in rheumatifms, and after 

 takinf cold, it is evident, the air can enter with all its qua- 

 lities, and vitiate the whole texture of the blood, and other 

 juices. 



From the palfies, vertigoes, and other nervous affeftions 

 caufed by damps, mines, Uc. it is evident, that air thus 

 cualined can relax and obftruft the whole nervous fyilem. 

 And from the colics, fluxes, coughs, and confumptiona 

 produced by damp, moift, and nitrous air, it is evident it 



can corrupt and fpoil the noble organs, &c. Sec Atmos- 

 PHERE, and preceding articles. 



AiR-/'(y, in Bo/any, a dillended bladder like feed-veflil, 

 opening on one fide, as in the periwinkle, or bladdtr-fcna. 

 It fignifies alfo other kinds of dillended air-vtlfels. Sec 



Foi.LlCULUS. 



i\\v.-ballooi<s, a name lately given to thofe aeroftatic ma- 

 chines that have been employed in aerial navigation. Sec 

 Akrostation. 



An:-ilaMer, in Ichthyolo^, a kind of veficula, contain- 

 ing elatlic air, found in the bodies of fifh, by means whereof 

 they are enabled to fullain themfelves in any depth of water, 

 and either to rife or fink at pleafure. 



The air-bladder is the fame with what is otherwife called 

 the fwim, or fwimming-bladdcr. This memliranous bag lie* 

 clofe to the back-bone, and is furniflied with a llvong mnf- 

 cular coat, by which it has the power of contraftion and 

 dilatation. It is connefted with a glandular fnbllance, which 

 contains a quantity of red blood ; and fi)me have fuppofed 

 that the air contained in tlie fwimming-bladder, is derived 

 from this fnbltanee. Two procelTes or appendices ifl"ue from 

 its anterior part, and terminate in the fauces ; and it is fup- 

 pofed by fome writers to be that part which is called the 

 Joiint!. 



The difcover)' of the life of the air-bladder took its rife 

 from obferving, that a bulible of air in rifing from the 

 bottom of a fluid, continually dilates till it reaches the top, 

 by reafon of the continual diminution of the weight, or 

 preffure, of the incumbent water. For the air, in the blad- 

 der, is like the bubble, more or lefs comprcffed, according 

 to the depth the fifli fwlms at, and takes up lefs or more 

 fpace ; and confequently the body of the fifli, part of 

 whofe bulk this bladder is, is greater or lefs according to 

 the feveral depths, though it retains the fame weight. The 

 rule of hydroftatics is, that a body heavier than fo much 

 water as is equal in quantity to the bulk of it, will fink ; a 

 body lighter, will fwim ; a body of equal weight will refl: 

 in any part of the water. By which rule, if the fiili in the 

 middle region of the water be of equal weight with an equal 

 bulk of the water, the fifli will reli there, without any ten- 

 dency either upwards or downwards ; and if the fifli be 

 deeper in the water, its bulk becoming lefs by the compref- 

 .fion of the bladder, and yet retaining the fame weight ; it 

 will fink and red at the bottom : on the other fide, if the 

 fifli be higher than the middle region, the air dilating itfelf, 

 and the bulk of the fifli confequently increafing, without 

 any increafe of the weight, the filh will rife and rell at the 

 top of the water. 



Perhaps the fifli by fome aftion can emit air out of tli^ 

 bladder, and afterwards out of its body ; and alio when 

 there is not enough take in more air, and convey it to this 

 bladder ; in which cafe it will be no wonder, that there 

 fliould be always a fit proportion of air in the bodies of all 

 fiflies, to ferve their ufe, according to the depth of water 

 they live in : perhaps alfo, by fiimc mufcle, the fifh can con- 

 tract this bladder beyond the preffure of the weight of wa- 

 ter ; and perhaps it can by its fides, or fome other defence, 

 keep off the preffure of the water, and give the air leave to 

 dilate itfelf. In thefe cafes, the fifh will be helped in all 

 intermediate diftances, and may rife or fink from any region 

 without moving a fin. 



If the air-bladder of a fifli be pricked or broken, ths 

 fifli prefently finks to the bottom, unable either to fupporl 

 or raife itfelf up again. Flat filhes, as folcs, plaife, &c. 

 which always lie groveling at the bottom, have no air« 

 "bladder. 



Dead 



