Transport of AIr Along Sheaths of Pulmonic Blood Vessels From Alveoli to Mediastinum

EXPERIMENTAL INVESTIGATIONS Pulmonic Interstitial Emphysema. —That air, after it has broken from the pulmonic alveoli into the interstitial tissue of the lung, can travel along the sheaths of the pulmonary blood vessels, in artificial channels which it dissects for itself, to the root of the lung, and from there into the mediastinum, has been amply demonstrated in a series of experiments on cats and other animals.1The alveoli are made to leak by overinflating them, and so stretching and straining the walls. This is accomplished by passing a truncated catheter into a region of the lung (the lower lobe of the right lung is conveniently used) and blowing air into it, thus extending the alveolar walls and producing many small ruptures in their floors, which overlie the small branches of the pulmonary blood vessels. It is important to visualize clearly this locus of the leakage,2the area of