The Oxygen Tension in the Submaxillary Glands and certain other tissues

At first sight it is perhaps not surprisinig that the various secre- tioIns of the body should be credited with a certain quantity of oxygen as well as of nitrogen.These gases are, no doubt, in a conditioni of simple solution and were they in the proportionis in which they occur in serum their presence, on casual consideration, would not be sur- prising.On further investigationi, however, it becomes evident that these very secretions are formed by the passage of fluid through the cells of secretinig glands, these cells take up oxygen more rapidly than any other structures in the body are known to do, and therefore it is much more remarkable that such a secretion as saliva should contain as much oxygeni as does the serum, than it would be if the saliva containied nonie.It is, however, still more remarkable that saliva and milk Should be credited with conitaining more oxygen in solution than there is in the same volume of serum.The present paper conlsists of (i) a critical discussion of the analysis of the gases in saliva, which have been obtainied by previous workers, and from which it will appear that in the opiniion of the author these analyses are not seriously amiss; (2) a description of some experiments which confirm them ; (3) a discussion of the light thrown by the facts cited uponi the physiology of certain tissues.I. THE OXYGEN IN SALIVA Two physiologists have published analyses of the oxygen in saliva.The following data are given by Pfliger': Quantity of Oxygen Nitrogen saliva per cent.per cent.36 56 c.c.