I. U N G S. 



'y'.aced chiefly on the left fide of the cheft, leaves a m;ich 

 narrower fpace for the bafis of the left than for that of the 

 -tight King. Tlie natural or accident;il varieties in the form 

 «r the cheft, as curvatures of the fpine, with the concomi- 

 tBnt deviations in the figure and direction of the ribs, are 

 always attended with correfponding varieties in the lungs. 

 We may defcribe in each lung, belid.-s the ba;:s and apex, 

 two furfaces, an internal and external. 



The external furface is convex in its whole extent, and 

 «orrcfp:nds to the thoracic parietcs, from which it is fepa- 

 ratcd by the pleura coftahs ; it is liaooth and polidicd, and 

 li'bricated by a ferous exhalation. A confiderable groove 

 U obferved in it, beginning behind a little below the apex, 

 and rutniing obliquely forwards ai\d downwards to the balis. 

 T'lis groove runs throughout the fubftance of the lung, 

 which it divides into two nearly equal iialvcs called lobes; 

 tiicfL' are conneftcd together at the root of the organ by the 

 r''floxion of the pleura, and by receiving their blood-veficls 

 £roai a common trunk. The two lobes are in contact with 

 each other by broad and flat furfaces, which are fmooih and 

 I'.ibricated, like the external furface of the lung, as they are 

 covered tliroughout by the pleura. The upper lobe of the 

 Rcht lung 13 marked by another groove, direilted obliquely 

 from abi>ve downwards, and within outwards; fo that its 

 mafs !S divided into three lobes : the middle is the fmallell, 

 and trian^^ular in its figure. This fecondary groove is more 

 variable than the former in its exillence, its length and depth. 

 Sometimes, but ver)- rarely, it is rot found ; and it is often 

 incomplete, io as not to divide the middle lobe entirely from 

 the fi:peri.)r. It is very feldom feon ii! the It-ft lung. 



The internal furface is nearly plane, and divided into two 

 unequal portions by the infertion of the bronchi and pulmo- 

 nary vefleli, which takss place towards its upper and back 

 part. 



It is at this point, which is called the root of the lung, 

 that the pleura is reflected over the organ : here, there- 

 fi-re, the pleura pulmonalis and coltalis are continuous. 

 This is the only fituation in which the lung adheres to the 

 containing cavity ; the furface is free and unattached every 

 ■where elfe ; it is fometimes caUed, from this circumllance, 

 the ligamentum pulmonis. 



The bronchus, the pulmonary artery and veins, the nerves 

 and lymphatics of the organ, furrounded and connected by 

 ocllular lubftance, and forming a fingle large fafciculut, 

 pafs out of the niedialliflum to the lung. The pleura is 

 r-eflefted over this fafciculus, covers it, and is continued 

 over the lung. That portion of the inner fide of the lung 

 which is behind the root i^ narrow, and correfponds to the 

 lateral furface of the vertebral column : the anterior divifion 

 ic broader, and is contiguoivs to the heart and pericardium ; 

 it is (lightly concave at this part. Above and below the 

 ififertion of the veffels the inner iurface of the lung is not di- 

 vided into thefi; two parts. 



The external and internal furfaces of the lung are united 

 by two edges. The anterior is thin, particularly below, 

 irregular in its outline, directed obliquely downwards and 

 forwards, and has in the left lung a fmall notch correfpond- 

 ing to the apex of the heart. The pofterior is obtufe, not 

 clearly marked, directed vertically, and correfponding to the 

 hollow at the angles of the nbs. On the latter is feeii, above, 

 the commencement of the great groove, which divides tlie 

 iung into two lobes. 



The bafis of the lung refts on the -diaphragm, and is con- 

 cave, to fuit the convexity of that great muTcular partition. 

 Jt is directed obliquely from within outwards, from above 

 downwards, and from before backwards ; correfponding in 

 ttis refpecl entirely to the diaphragm, Tlie concavity of 



the bafis is more marked in the right than in the left !iin(», 

 on account of the greater convexity of liiis fide of the dia- 

 phragm produced by the liver. The termination of the 

 great groove is found on this furface of the organ, fo that 

 tiie two lobes are dillintl here as well as in other fituations : 

 but the fuperior lobe coii'.ributes to tlic formation of the 

 bafis only in a very fmall part of its extent, ra'ticularly on 

 the right fide. The circumference of the bans prefentb a 

 thin edge, with a rather irregular outline intcrpofed betw«-en 

 the ribs and the diaphragm, near the attachment of the lat- 

 ter. This is more fenfible on tlnj ri^jht than on the left fide. 

 Its appearance varies according to the ditTerent states of 

 the lungs ; the preceding defcription applies to tlie dead 

 fubjeft. In infpiration, the diaphr5gm deic^nds a"d becomes 

 nearly plane ; the lung follows it, and affumes a correfpond- 

 ing figure, its edge, inllead of being thin, becuming thick, 

 and no longer included between the diaphrajzm and ribs. 



The apex of the lung is fmall and obtufe, and corre- 

 fponds to the cul-de-fac of the pleura under the firft rilx. In 

 tliis way it is completely infulated from the lower part of the 

 neck. It exhibits feveral more or le'.s marked tubercular 

 rifings. 



The whole furface of the lungs is unconnefted to the ira- 

 vity, except in the fituation ot the ligainerita pulmonum. 

 The oppofed furfaces of the lobes are in the fame way uucon- 

 nccted to each other, and covered by the ferous mem- 

 brane. All thefe parts are moiller.cd by a ferous exha- 

 lation. 



The colour of the hmgs, when not influenced by that of the 

 fluids which they contain, is extremely pale ; fometimes a flight 

 tawny brown, but more frequently grey or alh-coloured ; 

 and lometimts completely white. This colour is feen over 

 the whole organ, both on its furface, and in the interior, 

 when it is quite free from blood ; but is no !<jnger vifible 

 when the lung is loaded with that fluid. Hence we under- 

 iland why we meet with it fo feldom in the dead body, 

 fince a diltcntiun of the pidmonary veifels with blood is one 

 of the moll ordinary phenomena of death. The only cafes 

 in which we caa expeft with fome eertainty to find the 

 li4ngs exhibiting this pale colour throughout, are thofe of 

 deaths from hemorrhage. It was noticed by the Freuch in 

 individuals who peri(hed by the guillotine. We may often 

 obferve it in fome particular points of the organ, where the 

 abfence of blood may be afcertained by incilions. The 

 tawny or greyifh colour of the lungs is interrupted by fmaM 

 black or brown fpots, irregularly dillemiuated over the fur- 

 face, and very variable in number and form. Often the or- 

 gan is very thickly fpolted in this way ; at other times they 

 are fcattered here and there at confiderable dillances ; fome- 

 times, but very feldom, they do not exiil at all. Thefe 

 fpots do not depend in the leall on the blood. Simple in- 

 fpeCtiou is futficient to prove that they belong to the organi- 

 zation of the part. They are very dilUnft in the paleltand 

 moll bloodlefs luntjs, and may he eafily recognifed in the 

 general hvid tint of thofe w hich are moil loaded ; they fecia 

 to polfefs always the fame intenfity of colour; and they are 

 always circumfcribed, while the marks arifing from the blood 

 end imperceptibly. Thefe black fpots prefent every variety 

 of figure. Some are fuperficia], others extend into the fub- 

 ilance of the lung, and feme are found in the interior of tke 

 organ. They feem to belong entirely to the pulmonary 

 tilfue, as they are never feen on the bag of the pleura, and 

 are found in the fubftance of the lung. 



But generally the lungs are loaded with blood at the time 



of death, and do not confequently exhibit the palenefs which 



we have defcribed as belonging to their proper tiflue. They 



areuiually livid, TioletTColoured, brpwujlh,orreddiIh; and die 



4 L 3 inlxture 



