The term peritoneum derives from the Greek peritonaion, meaning to stretch around.  The first known recorded reference of the peritoneal cavity appears in the Ebers papyrus in 1550 BC¹. 

The Egyptians recognized that a sac surrounded the internal abdominal organs during their separation of the viscera from the rest of the corpse prior to embalmment.  Galen and many other prominent physicians of antiquity observed the peritoneum in the open abdomen of injured gladiators.  The early anatomists and surgeons described the extent of the peritoneal membrane, named its surfaces and attachments, but did not elaborate on its function or fine structure.  

The peritoneal membrane became of physiological interest to anatomists after the discovery of cells.  Von Recklinghaussen was the first to describe the gross and cellular anatomy of the peritoneum in 1862^2,3_.  Wegner described the effects of changes in body temperature occurring after intraperitoneal (ip) infusion of solutions with various temperatures⁴ and also reported the effects of concentrated dextrose or glycerin solutions on the volume of outflow obtained in the peritoneal effluent, perhaps the first evidence of osmotic ultrafiltration (UF).  Starling and Tubby expanded these observations by studying the bidirectional transfer of molecules across the peritoneal and pleural membranes and demonstrated the rapid absorption of isotonic solutions and slow absorption of serum⁵. 

By 1920, it had been recognized that, regardless of the infusate osmolality, the fluid was completely absorbed within 20 hours of infusion^6-8.  These observations led to the administration of ip fluids to infants with severe dehydration when the oral route was not possible^9,10.  This may have been the first therapeutic use of the peritoneal membrane.

The first quarter of the 20th century established the physiologic milestones for peritoneal dialysis (PD) with emphasis on the relationship between osmolality of the fluids and peritoneal ultrafiltration and absorption^7,11 and the bidirectional flux of small molecules between the peritoneal cavity and the intravascular compartment.  The contributions of Orlow, Clark, Putnam, and others confirmed the peritoneal membrane permeability for sodium and other minerals^12-16.  The concept of osmotic equilibrium between peritoneal fluid and plasma was established by Putnam in 1922, who concluded that mass transfer was driven by passive concentration gradients rather than active membrane transport¹³.   Klapp first observed that heat applied to the anterior abdominal wall could accelerate the exchange of substances between the ip cavity and the blood compartment¹⁵.  This observation was a precursor of the concept of augmentation dialysis.  Clark confirmed these findings  twenty years later by using ip infusions of warm solutions and suggested that vasodilatation was responsible for the accelerated rate of exchange¹⁶.  The initial uremic models consisted of rabbits and guinea pigs subjected to ureteral ligation.  Intraperitoneal exchanges lasting 2 to 4 hours were utilized.  Although there was moderate absorption of the dialysate due to its hypotonicity relative to uremic plasma, definite clinical improvement was noted in the animals after dialysis. 

References:

1. Cunningham RS. The physiology of the serous membranes. Physiol Rev 6:242,1926
2. von Recklinghaussen FT. Die Lymphgefässe und ihre Beziehung zum Bindegewebe. Berlin, Germany: Hirshwald; 1862
3. von Recklinghaussen FT. Zur fettresorption. Virchows Arch 26:172, 1863
4. Wegner G. Chirurgische Bermekungen über die Peritonealhöle, mit besonderer Berucksichtigung der Ovariotomie. Arch Klin Chir 20:51, 1877
5. Starling EH, Tubby AH. The influence of mechanical factors on lymph production. J Physiol (London) 16:140, 1894
6. Cunningham RS. Studies on absorption from serous cavities, III. Am J Physiol 53:488, 1920
7. Schechter AJ, Cary MK, Carpentieri AL, et al. Changes in composition of fluids injected into the peritoneal cavity. Am J Dis Child 46:1015, 1933
8. Hamburger HJ. Ueber die Regelung der osmotischen Spannkraft von Flüssigkeiten in Bauch-und Pericardialhöhle. Archiv f Phys du Bois-Reymond 281, 1895
9. Blackfan KD, Maxcy KF. The intraperitoneal injection of saline solution. Am J Dis Child 15:19, 1918
10. Weinberg M. Die Anwendung der intraperitonealen Infusion beim wasserverarmten Saügling. Ztschr f Kinderheilkunde 29:15, 1921
11. Leathes JB, Starling EH. On the absorption of salt solutions from the pleural cavities. J Physiol 18:106, 1895
12. Orlow WN. Einige Versuche über die Resorption in der Bauchhöle. Arch f Phys Pflüger 59:170, 1895
13. Putnam TJ. The living peritoneum as a dialyzing membrane. Am J Physiol 63:548, 1922
14. Abbott WE, Shea P. The treatment of temporary renal insufficiency by peritoneal lavage. Am J Med Sci 211:312, 1946
15. Klapp R. Ueber Bauchfelresorption. Mitt Grenzgeb der Med u Chir 10:254, 1902
16. Clark AJ. Absorption from the peritoneal cavity. J Pharmacol 16:415, 1921