more or less, of cellular tissue; in these cases, large cavities were almost always found; the more advanced and extensive the disease, the more dense usually were the adhesions. Dr. Hodgkin, in his Lectures on Morbid Anatomy, vol. ii. p. 177, says: "The contraction which accompanies the changes which this pleuritic deposit undergoes, in conjunction with alterations in the lung, from the consolidation of texture and contraction of excavations, is, I believe, the principal means which produces the alteration of form which sometimes accompanies the want of resonance at some parts of the chest, in phthisical patients." This remark of Dr. Hodgkin, with regard to the permanent contraction of the lung in such cases, is, I am convinced, to be applied, also, as the principal cause of the deficient, absent, or reversed motion of those parts of the chest occupied by the diseased lung. I have found, that if adhesions be loose, cellular, and long, even though they be universal, the lungs enlarge when distended to the normal

extent.

When the adhesions are tendinous, very strong, intercostal, passing from rib to rib, and embracing the lung in an unyielding tendinous sheath, as in the cases of Neale and Boot, then the lung can be distended but laterally very little, or not at all, although there is usually some descent of the diaphragm, and consequent elongation of the diseased lung, as is shown in the wood-cut, p. 441. In these cases, when the adhesions are cut across, the exposed tissue of the lung is usually in part expansible; but the adhesions prevent, or impede, the expansion.

In Pearson's case, the observations from whom were taken in articulo, the distention of the left lung, especially the upper lobe, was much restrained by intercostal adhesions, but not to the almost absolute extent found in Neale.

The impediment to expansion during life was, in these cases, proportioned to the strength and inexpansibility of the adhesions lining and restraining the ribs, and investing the lungs. It will be observed, that although all the movements were restrained, those of the thoracic and intermediate ribs

were so much more than those of the diaphragm and diaphragmatic ribs.

This will be found to apply to the thirteen cases in which there was, to a greater or less extent, consolidation of the lower lobe, and in all of which, except Neale, there were cavities of considerable size in the upper lobe.

The dimensions and respiratory movements of the opposite, or less diseased lung, were notably exaggerated. This exaggeration extended, in nearly all the cases, through the whole lung, the costal and diaphragmatic motion being alike increased.

The inspiratory elevation, and outward movement of the ribs, draws the sternum very palpably over to the unaffected side, a point to which my pupil, Mr. Martyn, drew my attention. In Neale's case, it was well seen that the sternum is drawn to the right by the right costal expansion; and in Boot's, to the left, by the expansion of the left side. (See wood-cuts at pp. 440, 441.)

When the right lung is affected, as in Boot, the exaggerated expansion of the left lung covers the heart during inspiration, and often causes the disappearance of its impulse, from the intercostal spaces, and its appearance below the xyphoid cartilage.

When the left lung is affected, as in Neale, owing to its deficient expansion, the heart is not further covered by it during inspiration, and its impulse, instead of being lessened in the intercostal spaces, is increased, as the heart is drawn downwards.

In Neale, the liver is pushed down extensively by the descent of the right side of the diaphragm, the stomach descending but little; while in Boot, the stomach is pushed extensively downwards, the liver descending but little. Out of thirteen cases, in which the lower lobe was more or less diseased, and in nine of which the left, and four the right, lung was affected, the sixth costal cartilages retracted during inspiration in ten, and the lower end of the sternum in six; in eight of the cases there was retraction of the sixth cartilage through the

.

whole inspiration; in the other two, only at the beginning. In one of the excepted cases-Elliott (Table III., Case 143,)— the lower end of the sternum fell back at the beginning of inspiration; and in the other-Pearson (Table III., Case 148,) -who was observed in articulo mortis, the abdomen retracted during inspiration at the centre, the costal action was consequently throughout exaggerated: in her, the ribs over the affected side protruded slightly, and the abdomen considerably, at the beginning of inspiration.

The retraction was, in these instances, as in those where it occurred from condensation, due to the rapid elongation and collapse of the lower portion of the lung, by the descent of the diaphragm. (p. 436).

In two of the cases, the upper end of the sternum fell back throughout, and in four, just at the beginning of, inspiration. This partial retraction of the upper end of the sternum might be due, in some of the cases, to obstruction to inspiration, from laryngitis. But we shall have to consider another cause, residing in the non-expansibility of the thickened walls of the cavity.

Cavities in one upper lobe.-I have observations of twentyfour cases in which there were cavities in one upper lobe; the upper lobe of the opposite lung was in all the cases notably less diseased, and the lower lobes of both lungs were not appreciably affected. All those cases in which the whole of one lung was diseased have been already taken out and placed in the previous subsection.

Of the 13 cases in which the whole of one lung was more or less solidified with cavities in the upper lobes

in

9, the left was affected. 4, the right

The accompanying lithographs from daguerreotypes of Samuel Redgate, (Table III., Case 163,) the once celebrated fast bowler, illustrate the change in the visible form of the chest, and the position of the viscera during a deep inspiration. In the daguerreotype taken during tranquil respiration,