178 r %jT 



been seen, that of these pulmonary phlegmasise, the commonest and least 

 serious catarrh consists in inflammation of the mucous membrane which 

 lines the air passages, whilst the real peripneumony has its seat in the 

 parenchyma of the organ, which it converts into a hard and compact 

 mass. It is this state that anatomists have long designed under the nam.c 

 of hepatization, because, in fact, the substance of the lung has acquired 

 the hardness, the weight, and something of the appearance of the liver. 

 The same anatomical researches have shown that pleurisy consists in 

 inflammation of the pleura, and of the surface of the lung, an inflamma- 

 tion which sometimes leaves no trace, but which oftener exhibits, on the 

 opening of bodies, the pleura thickened and opaque, covered with a layer 

 of coagulabie lymph, whitish, more or less thick, or even adhering to 

 the lung*. 



There arise from the surface, and from the internal substance of the 

 lungs, a prodigious number of absorbents, which may be divided into 

 superficial and deep seated. The latter accompany the bronchial tubes, 

 and penetrate into the substance of th& glandular bodies situated where 

 those air-vessels divide, but collected, in greatest number, towards the 

 root of the lungs and at the angle formed by the bifurcation of the tra- 

 chea. These bronchial glands, belonging to the lymphatic system, do 

 not differ from the glands of the same kind, and are remarkably only by 

 their number, the size, and their habitually darkish colour. The absorb- 

 ents of the lungs, after ramifying in these glands, terminate in the upper 

 part of the thoracic duct, at the distance of a few inches from its termi- 

 nation into the subclavian vein. Lastly, the lungs, though endowed with 

 a very imperfect degree of sensibility, have a considerable number of 

 nerves furnished by the great sympathetic, and especially by the eighth 

 pair. 



It was long believed, on the authority of Willis that the aerial tissue 

 of the lungs is vesicular, that each ramification of the bronchise termi- 

 nated in their substance, in the form of a small ampullula; but at pre- 

 sent, most anatomists adopt the opinion of Helvetius. According to 

 Helvetius, every air-vessel terminates in a small lobe, or kind of sponge 

 fitted for the reception of air, and formed of number of cells communi- 

 cating together. These lobes, united by cellular tissue, form larger 

 lobe-s, and these together form the mass of the lungs. 



The tissue that connects together the different lobes is very different 



* These adhesions of the lung to the pleura costalis, are so, common, that the old 

 anatomists considered them as a natural disposition, and called them ligaments of the 

 Jungs. It has been believed till now, that these adhesions arose from the organization 

 of a substance transuding from the two surfaces. Numerous dissections have con- 

 vinced me, that in all the points where they are met with, the pleura has disappeared, 

 that it is decomposed, and that, whether it he at the surface of the lungs, or within 

 the ribs and the muscles, it is produced by the act of inflammation, that it is become 

 cellular, by the thinning of its tissue and the separation of its lamina. The pleura 

 thus reduced to cellular tissue, the adhesion is produced by the first intention, in the 

 same way as in simple wounds immediately united. There is no organ that abounds 

 more than the lungs in facts important to morbid anatomy. The variety of appearances 

 they exhibit, on the opening of bodies, are almost innumerable; and to give one in- 

 stance, the pleura appears after pleurisy in five perfectly distinct conditions. 1st. In its 

 natural state, when the disease being incipient and slight, the resolution is effected at 

 the moment of death. 2dly. When it is red, thickened, and opake. 3dly. When it 

 is covered with coagulabie "lymph. 4th ly. When it adheres. Sthly. When, in conse- 

 quence of chronic inflammation, hydrothorax has taken place, &c. &c. Author's Note. 



