Jean-Antoine “Abbe” Nollet (1700 – 1770) was a scientist and a priest. He was noted for his scientific experiments with electricity, physics and for discovering Osmosis (1748). He conducted a simple experiment with water, a membrane from an animal bladder, and wine. Perhaps: he just wanted to find out why his Pee was yellow instead of purple. A column of wine was capped at the bottom with an animal bladder membrane. The membrane end was placed in water. He expected to see how well the membrane filtered the color from the wine.
Instead, pure water flowed uphill through the membrane into the wine. It required a substantial pressure applied to the wine to stop the flow of water. This was a perplexing discovery. Water and Wine are essential components of the Sacrament of Holy Communion.
It took more than one hundred years for experimenters to find the that other solutions worked as well as wine. Sugar water solutions gave the most repeatable results. The process is called Osmosis: the spontaneous flow of water through a membrane into a solution. Since the membrane allowed water flow but not sugar, Jacobus H. van’t Hoff suggested that the membrane was semi-permeable. It allowed water to pass but did not allow sugar molecules. Various solutes were tried but the sugar water solutions produce the most repeatable results.
Van’t Hoff won a Nobel Prize in Chemistry (12/13/1910). He discovered a relation between osmotic pressure and thermodynamics. We will review van’t Hoff’s Nobel Lecture next month.
Since then, others have noted some problems with van’t Hoff’s work. We note that medical. Biological, and water purification specialists have defined unique terms for their views of osmosis. This is like ancient Indian folklore about “the blind men and the elephant”. Each sees the elephant from his own point of view, one touches the side and sees a wall, another grabs the tail and views a rope. It is time that we see the entire elephant.
We proposed that the osmosis transport process is a molecular flow not a bulk flow process (© 2001)
© Larry Howlett HTMD Engineering 2020
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