Properties, function and origin of the alveolar lining layer.

TLDR: Equally stable foam is found in the bronchi of an animal the respiratory movements of which have been paralysed and into the trachea of which a mixture of oxygen and ammonia gas has been insufflated for one or two hours.

Abstract: IN acute lung œdema in the rabbit, fluid a ad foam are found in the trachea. This foam has an altogether peculiar property, in that it is unaffected by silicone anti-foams; these rapidly destroy the foams produced by shaking œdema fluid or blood serum with air. Equally stable foam is found in the bronchi of an animal the respiratory movements of which have been paralysed and into the trachea of which a mixture of oxygen and ammonia gas has been insufflated for one or two hours; similar foams are obtained from healthy lung by cutting and squeezing under water, or after introduction of saline into the trachea. The stability of such foams is due to an insoluble surface layer on the bubbles; this layer can be attacked by pancreatin or by trypsin.