But the pleura or membrane covering the lungs

But the pleura or membrane covering the lungs

But the pleura or membrane covering the lungs

The lungs have been, in the first instance, inflamed, but the pleura or membrane covering the lungs, and also lining the chest, has likewise become by the progress of the disease involved. The cavity has become full of water, or rather serum, and by the pressure of the fluid the organs of respiration are compressed. It is seldom that both sides are gorged to an equal degree; but one cavity may be quite full while the other is only partially so. One lung, therefore, in part remains to perform the function on which the continuance of life depends; and if, by any movement, the weight of fluid is brought to bear upon the little left to continue respiration, the animal is literally asphyxiated. It drops, in fact, strangled, or more correctly, suffocated; and as the vital energy is strong or weak, so may the dog more or less frequently recover for a time. In the end, however, the tax upon the strength exhausts the power, and the accumulation of the fluid diminishes the source by which the life was sustained. After death, I have taken from the body of a full-sized Newfoundland one lung, which lay with ease upon my extended hand; while the two held together afforded a surface sufficient to support the other. The condensation was so great that the part was literally consolidated, and the fluid which exuded on cutting into the substance was small in quantity. The blood-vessels were, with the air-cells, compressed, and while the arterialization of the blood was imperfect, the circulation was also impeded.