Breathing an atmosphere that contains the normal amount of oxygen but a large excess of carbon dioxide results in a tissue acidosis as well as one of the blood. The extravascular changes in reaction take place with far greater speed than when acidosis is induced with hydrochloric acid, and they do not persist as in the case of this latter but swiftly disappear when the animal breathes ordinary air once again. The changes parallel closely in magnitude and time those occurring in the blood. The same matrix tissues are rendered acidotic is when hydrochloric acid is administered.
The blood alkalosis that results from a blowing off of carbon dioxide is accompanied by an extravascular alkalosis. Under the circumstances of our experiments the connective tissue became more alkaline than ordinary but no change was noted in the cartilage, a fact to be explained by the slight degree of the alkalosis and its brief duration.