Polywater was a hypothetical polymerized form of water that was the subject of much scientific controversy during the late 1960s.

The Soviet physicist Nikolai Fedyakin , working at a small government research lab in Kostroma, Russia, had performed measurements on the properties of water that had been condensed in or repeatedly forced through narrow quartz capillary tubes. Some of these experiments resulted in what was seemingly a new form of water with a higher boiling point, lower freezing point, and much higher viscosity than ordinary water, about that of a syrup.

Boris Derjaguin, director of the laboratory for surface physics at the Institute for Physical Chemistry in Moscow, heard about Fedyakin's experiments. He improved on the method to produce the new water, and though he still produced very small quantities of this mysterious material, he did so substantially faster than Fedyakin did. Investigations of the material properties showed a substantially lower freezing point of −40 °C or less, a boiling point of 150 °C or greater, a density of approx. 1.1 to 1.2 g/cm³, and increased expansion with increasing temperature. The results were published in Soviet science journals, and short summaries were published in Chemical Abstracts in English, but western scientists did not notice the work.

In 1966, Derjaguin travelled to England for the "Discussions of the Faraday Society" in Nottingham. There he presented the work again, and this time English scientists took note of what he referred to as anomalous water. English scientists then started researching the effect as well, and by 1968 it was under study in the United States as well.

A scientific fervor followed. Some experimentalists were able to reproduce Derjaguin's findings, while others failed. Multiple theories were advanced to explain the phenomenon, and some researchers predicted that if polywater were to contact ordinary water, it would convert that water into polywater, echoing the doomsday scenario in Kurt Vonnegut's novel Cat's Cradle. The actual existence of polywater was no longer questioned by many; some were even proposing that it was the cause for increasing resistance on trans-Atlantic phone cables.

During this time several people questioned the authenticity of what was now known in the West as polywater. The main concern was contamination of the water, but the papers went to great lengths to note the care taken to avoid this. However Denis Rousseau of Bell Labs decided to experiment with his own sweat after playing a baseball game at the lab, and found it had identical properties. He then published a paper suggesting that polywater was nothing more than water with small amounts of biological impurities.

Another wave of research followed, this time more tightly controlled. Invariably the polywater could no longer be made. When subjected to chemical analysis, samples of polywater were invariably contaminated with other substances (explaining the changes in melting and boiling points), and examination of polywater via electron microscopy showed that it also contained small particles of various solids, explaining its higher viscosity.

When the experiments that had produced polywater were repeated with rigorously cleaned glassware, the anomalous properties of the resulting water vanished, and even the scientists who had originally advanced the case for polywater agreed that it did not exist. This took a few years longer in the Soviet Union, where they thought they were "on to something".

Denis Rousseau used polywater as a classic example of pathological science, and has since written on other examples as well.

See Also

• Penta Water
• Water memory