conservation for art is "preserving, fixing, or just restoring old art or other things like artifacts etc." (found in an article on www.msaconservation.com) it's most likely controversial because if something's old and valuable, people want to keep it in it's original form. (just a guess) but that's how it is in the art world.
I don’t know but she fine ;)
Not sure if this is what you need.... but....it is the teaching of the Catholic Church that in the Eucharist the appearance is quite unchanged, but the basic reality has become the body and blood of Christ.
The change from bread and wine to a presence of Christ that is true, real, and substantial is called transubstantiation.
I believe it was either the Sumerians or the Mesopotamians, hope this helps! :-)