There’s a nice article in Slate about the polywater controversy of the 1960s and 70s.
Polywater is supposed to be a novel state of water. In this state, H20 is denser, has a lower freezing point and higher boiling point, is oily, and has several other features that are quite different from the everyday water we drink and bathe in.
So there are parallels here to claims about homeopathy; in both cases ordinary water is supposed to have extraordinary abilities.
In the case of polywater, science took a few years to self-correct, but it was eventually decided that the samples of “polywater” weren’t pure H20 after all. So, should the scientists discussing polywater have been more careful? Were politicians too eager to “close the polywater gap” with the Soviets?