Page:A Treatise on the Membranes in General, and on Different Membranes in Particular.djvu/88

84 SEROUS MEMBRANES. that I have several times observed in living animals, that the exhalation from the serous surface of the lower belly, does not increase during digestion, or at least if it is greater, absorption becomes more active, and that thus the surface of the peritoneum is no more humid than at other times.

I have opened the chest of many Guinea pigs, after making them run a long time to accelerate their breathing, nor have I been able to remark any increased humidity on the pleura.

114. What is the nature of the fluid of the serous cavities? In the pathologic state, in different dropsies, its albuminous nature is placed beyond doubt by the action of fire, of alkohol, and of the acids. It is difficult to analyse it in the sound state.

Hewson however, having collected a spoonful of it in large animals, found its composition the same as that of the fluid circulating in the lymphatic system, as that of the serosity of the blood, which is equally albuminous. The trials of this author, whose results every thing seems to confirm, need however to be repeated.

115. As to the humour of the articular surfaces and of the tendinous sheaths, it seems, though very analogous to that of the cavities, to differ from it by the nature of the albumen it contains. See on this subject the analysis made of it in the Annals of Chemistry.

116. The principal use of this fluid in lubricating the surfaces, is to prevent adhesions, an inevitable effect without it, of the friction which they experience.