AUSCULTATION. 



239 



mcath and province of Leinster that on the wes- 

 tern bank was termed Irish Town, it was th 

 part most strongly fortified, and is situated in the 

 Bounty of Roscommon and province of Connaught. 

 On the Connaught side of the river there is a cas- 

 tle, said to have been erected, or at least enlarged 

 and strengthened, by King John. This castle, 

 which has been re-edified in a modern style of forti- 

 fication, commands the bridge which connects the 

 town. was once the residence of the lord-presi- 

 dents of Connaught, and has been the scene of 

 stirring events. The bridge was built, in the reign 

 of Queen Elizabeth, by Sir Henry Sidney, Lord 

 Deputy of Ireland, and has survived the accidents 

 of war, as well as the wear of time and traffic. It 

 is only twelve feet wide ; and being the highway 

 from Connaught into Leinster, it is a great thor- 

 oughfare, and is often disagreeably thronged. In 

 the centre of the bridge is a stone monument, bear- 

 ing an inscription, nearly obliterated, setting forth 

 that, " in the ninth year of the reign of our most 

 dere soveraign ladie Elizabeth, this bridge was built 



by the device and order of Sir Henry Sidney, knt., 

 who finished it in one year, by the good Industrie and 

 diligence of Peter Levis, elk., Chanter of the Ca- 

 thedral Church of Christ, Dublin, and steward to 

 said deputy." 



The town of Athlone was incorporated by char- 

 ter from James the First, and received a further 

 charter from Charles the Second. What chiefly 

 renders the town of importance is its being a sta- 

 tion, or government depot for troops and military 

 stores. There are barracks for the reception of 

 2000 men, to which an ordnance-yard, magazines, 

 and hospital are attached. Some trade is carried 

 on by means of an extensive brewery and two dis- 

 tilleries, and by the manufacture of felt-hats. 

 Markets are held three times a week. Athlone 

 is well situated for trade. The Shannon is navi- 

 gable tor thirty-eight miles farther up than the 

 town ; the navigation, which is interrupted by the 

 bridge and ford, being continued by means of a 

 canal, cut on the Connaught side of the river, by 

 which also the distance is shortened, as the Shan- 

 non makes here a considerable sweep. The Grand 

 Canal, also, which communicates with Dublin, 

 joins the Shannon seventeen miles below Athlone. 

 Population in 1841, 6393. 



AUSCULTATION, AND PERCUSSION, in 

 medicine ; terms applied to the methods used to 

 ascertain the seat and nature of disease, by the 

 signs which may be recognized by the sense of 

 hearing. They comprise the study of all sounds 

 indicative of disease, whether heard by the un- 

 assisted ear, or through the medium of instruments, 

 and whether arising naturally, or produced arti- 

 ficially. 



From the earliest ages, physicians have known 

 that disease in the cavity of the chest might occa- 

 sionally be detected by the ear; but it was not till 

 about seventy years ago that any express rules 

 were laid down upon this subject. The merit of 

 being the first methodical auscultator is due to Dr 

 Avenbrugger, a physician of Vienna, who pub- 

 lished a short treatise on this subject in the year 

 1761. It is written in Latin, and is entitled, "A 

 New Discovery of the Art of Detecting Diseases 

 in the Interior of the Chest by Percussion." 

 When the chest of the patient is struck by the 

 fingers of the physician, if it is healthy, it gives a 

 sound, says Dr Avenbrugger, like that of a drum 

 covered with cloth; whereas, if it is diseased, the 



sound produced is as if solid flesh had been struck. 

 In performing this examination, the chest of the 

 patient must be covered with his shirt, or else the 

 fingers of the physician with a glove, which must 

 not be made of glossy leather ; for if the bare chest 

 is struck with the bare hand, the concussion of 

 smooth surfaces produces an external sound which 

 obscures the internal one. The following general 

 rules are clear, correct, and well-expressed: 



The duller the sound is over the chest, and the 

 nearer it approaches the sound of solid flesh, the 

 greater is the disease. 



The larger the space over which this dulness 

 extends, the greater is the disease. 



It is worse for the left side to be affected than 

 the right. 



It is less dangerous that the front and upper part 

 of the chest (viz., from the collar-bone to the 

 fourth rib) should be destitute of sound than the 

 lower part. 



If one side of the chest is entirely destitute of 

 sound, it is a fatal sign. 



If the sternum (viz., the front and central part 

 of the chest) is without sound, it is a fatal sign. 



If the place which the heart occupies gives the 

 sound of solid flesh over a great space, it is a fatal 

 sign. 



Dr Avenbrugger's little manual is not confined 

 solely to the signs afforded by percussion ; in many 

 instances he gives a succinct but masterly outline 

 of the general symptoms by which various diseases 

 of the chest may be recognized. In offering his 

 work, the fruit of seven years' observation, to 

 physicians, he remarks, that, in treating diseases of 

 the chest, the sound obtained by percussion is in- 

 ferior in importance only to the pulse and respir- 

 ation. Avenbrugger's work has never been trans- 

 lated into English ; but there is a French version of 

 it by Corvisart, in which the brief axioms of the 

 German physician are illustrated, and almost over- 

 whelmed, by a most copious commentary. This 

 translation, however, is a valuable work, and an 

 additional step in the art of auscultation. With 

 this exception, but little advance seems to have 

 been made from Avenbrugger to Laennec, the dis- 

 tinguished inventor of the stethoscope, (see Stetho- 

 scope, in the body of the work.) This is a tube, 

 usually made of wood, one end of which is applied 

 to the chest of the patient, and the other to the 

 ear of the physician. By this contrivance, the 

 sound of the patient's respiration, as well as voice, 

 is transmitted in the most distinct manner, and the 

 minutest variations from the healthy standard can 

 be distinguished by a practised ear. In children, 

 for instance, the sound produced by respiration is 

 louder and more acute than in adults ; but this 

 acute breathing often occurs in grown-up persons, 

 when, one lung being diseased, the other is forced 

 to do work for both. It is known among stetho- 

 scopists by the name of puerile respiration. Or, 

 let us suppose a patient in an advanced stage of 

 consumption, in whose lungs cavities have been 

 formed by the suppuration of tubercles ; if the 

 stethoscope be applied to the chest of such a pa- 

 tient when he is speaking, his voice will be heard 

 echoing from the cavities in his lungs : this morbid 

 resonance is called pectoriloquy. 



The principle, on which auscultation and per. 

 cussion are applied to the detection of disease, is 

 sufficiently plain. Indeed, it is often used in the 

 common affairs of life. The carpenter strikes his 

 hammer against the wall, to ascertain where to 



