TUB 



TUB 



there is no occafion to take it off, becaufe it takes fire as 

 quick as loofe powder. 



The French ufe a fmall reed, to which is fixed a wooden 

 cap, and they are about two inches long, filled with mealed 

 powder, moiftened with fpirits of winp ; and a fmall hole is 

 made through them of the fize of a needle, through which 

 the fire darts with great violence, and gives fire to the 

 cartridge, which muft be pierced before-hand with the 

 priming-iron. 



Thefe tubes may be kept a great while without being 

 fpoiled ; but piercing of the cartridge retards the quicknels 

 of firing. Muller's Art. p. 293. 



Tube, Alimentary. See Duct. 



Tube, Eujiachian, or Trumpet, in Anatomy, a canal of 

 communication between the throat and the tympanum. See 

 Ear. 



Tube, Eujiachian, Difeafe and ObJlruBiom of, in Surgery. 

 Thefe are often a caufe of a confiderable degree of deaf- 

 uefs, becaufe it is neceffary for perfcft hearing, that air 

 (hould be conveyed from the mouth through this paflage 

 into the cavity of the tympanum, which now can no longer 

 happen. 



A degree of deafnefs generally attends a fevere cold, 

 which is accounted for by the Euftachian tube being ob- 

 ftrufted with thickened mucus. Mr. Saunders tells us, that 

 the obftruftion mott frequently arifes from fyphilitic ulcers 

 in the throat, or floughing in the cynanche mahgna. The 

 deafnefs comes on when fuch fores are healed, that is, when 

 the obftruftion is complete. The defcent of a nafal polypus 

 into the pharynx, and enlarged tonfils, have alfo been known 

 to clofe the tube. 



When the Euftachian tube is obftrufted, the patient can- 

 not feel the membrana tympani crackle, as it were, in his 

 ear, on blowing forcibly with his nofe and mouth flopped. 

 Previous ulceration, or difeafe, of the throat, will fome- 

 times aid in facifitating the diagnofis. 



When the Euftachian tube is obftrufted with mucus, it 

 has been propofed to employ injeftions, which are to be 

 thrown, by means of a fyringe and catheter, into the guttural 

 orifice of that canal. This operation, however, is alleged 

 to be always attended with trouble ; and when the os fpon- 

 giofum inferius happens to be fituated near the floor of the 

 orbit, the introduftion of any inftrument like a female ca- 

 theter would be imprafticable. Richerand Nofographie 

 Chirurgicale, tom. ii. p. 131. edit. 2. 



Mr. A. Cooper had noticed, that hearing was only im- 

 paired, not loft, when fuppurations in the tympanum had 

 injured, and even deflroyed the membrana tympani ; and 

 that the degree of deafnefs by no means equalled what re- 

 falted from an obflruftion of the Euftachian tube. Hence, 

 when the tube was permanently obUterated, he conceived 

 that a fmall punfture of the membrana tympani might be 

 the means of enabling the patient to hear. Mr. A. Cooper 

 praftifed the plan with fuccefs, and others have imitated him 

 with the fame refult. 



The operation confifts in introducing an inftrument, re. 

 fcmbhng a hydrocele trocar, but curved, into the meatus 

 auditorius externus, and pufliing it through the anterior and 

 inferior part of the membrana tympani ; a place rendered 

 moft eligible, on account of the fituation of the chorda 

 tympani and manubrium of the malleus, parts which fliould 

 be left uninjured. The inftrument muft not be introduced 

 far, left it fliould wound the vafcular lining of the tym- 

 panum, and caufe a temporary continuance of the deafnefs, 

 by an effufion of blood. When the punfture is made, in 

 proper cafes, and in a judicious manner, hearing is mimedi- 



I 



ately reftored. A fmall hole in the mfembrana tympani now- 

 conveys the air into the cavity of the tympanum, anfwering 

 the fame purpofe as the Euftachian tube. 



The furgeon will be able to operate with more eafe, if he 

 take care to leflen the curvature of the meatus auditorius, by 

 drawing upward the external ear. 



There is fome chance of a relapfe, in confequence of the 

 opening clofing up. This confideration has led Richerand 

 to propofe making the aperture with cauftic, fo as to de- 

 ftroy a part of the membrane. ( Nofographie Chirurgicale, 

 tom. ii. p. 132. edit. 2.) The fuggeftion is not, however, 

 likely to be adopted, on account of the inconveniences of 

 applying cauftic within the ear. Mr. Saunders is an advo- 

 cate for making the opening large. This gentleman relates, 

 that he inftantaneoufly reftored hearing in one cafe, in which 

 the patient had been deaf thirty years, in confequenice of a 

 lofs of part of his palate by fyphilis. Mr. A. Cooper's 

 cafes are in the Philofophical Tranfaftions for 1802. 



Punfturing the membrana tympani has been attended 

 with fome degree of fuccefs in France, as well as this 

 country. It is not to be diflembled, however, that there 

 are numerous failures. We are informed that profeflor 

 Dubois has done the operation in four inftances, without 

 fuccefs. Richerand Nofographie Chirurgicale, tom. ii. 

 p. 132. 



In moft cafes, the patients who have been benefited, are 

 faid to have experienced pain juft after the trocar was with- 

 drawn. The organ, in confequence of not being accuf- 

 tomed to found, had become fo extremely fenfible, that it 

 could not bear the gentleft impreflion of the fonorous vibra- 

 tions ; and the patient's firft requeft, after the perforation 

 was made, was that they who were near him might fpeak 

 foftly. This exceflive tendernefs of the fenfe gradually 

 fubfides. 



Tubes, Fallopian, or Trumpets, in Anatomy, two fmall 

 canals, forming communications between the cavities of the 

 uterus and abdomen, and ferving to convey the germs of 

 the new beings, in generation, from the ovaries to the uterus. 

 See Generation. 



Tube, Glafs. See Glass-Tu^, L.AMP-£lowers, and 

 Hermetical Seal. 



In order to bend a glafs-tube, if the glafs is pretty thick, 

 and the bore narrow, it may be held in the weaker part of 

 the lamp-flame, and foftened for about an inch or two of its 

 length, and then bent flowly into any required fliape. But 

 if the tube be w ide, and the glafs thin, this mode of bending 

 will entirely deftroy the cylindrical form of the bore at the 

 part that is bent, making a double flattening. In order to 

 avoid this, firft feal up one end of the tube, and then, whilft 

 bending it at the required part, blow fteadily and gently 

 into the open end, and the prefl"ure of the breath wiU coun- 

 teraft the faUing in of the fides of the bending portion, and 

 keep the bore cyhndrical. The clofed end is then cut off 

 by the file ; for which purpofe, make a deep fcratch with 

 one edge of a fine three-cornered file on the part intended to 

 be cut, then break the tube with a fmart pull in that direc- 

 tion in which the fcratched part will be outermoft ; and it 

 will in general feparate accurately at this point. 



In order to join two tubes, heat them both in the flame, 

 and apply them together, when quit hot, turning them 

 round to finifli the confolidation ; or elfe, to avoid the thick 

 ring of g'afs which this produces, previoufly clofe one end 

 of one tube, and when the two ends are fully joined, blow 

 into the open end of the other tube, and pull them out a httle 

 at the point of junfturc, till an equal cyhnder is formed. 



To form a bulb (e-g- of a thermometer), chufe a lube 



of 



