Nature uses various natural membranes to eliminate toxic substances fr
om the blood, Uremia treatment mainly in renal failure. The membranes
used for this purpose are predominantly those of the gastrointestinal
system and the skin. Humans tried to imitate nature, and employed the
same membranes for blood purification in patients with renal failure.
The beginning of the practice can be dated to at least 4,000 years ago
. However, the initiative for such clearing maneuvers was given by the
human mind's conception for purifying the cosmos, the polls and the s
oul. This article traces similarities between such metaphysical tactic
s and procedures of the applied sciences. It also describes the histor
ical evolution of the use of natural membranes for medical reasons in
nephrological patients.