By manipulating the hole, one gas could be made hotter and the other cooler.
Leon Brillouin resolved the paradox by showing the entropy increase made in choosing outweighs the decrease resulting from execution. In the original version, two isothermal gases were joined at a small hole.  By manipulating the hole, one gas could be made hotter and the other cooler. For ten points, what netherworld being, first summoned by a Scottish scientist, seemed to use this method to violate the laws of thermodynamics?
Leon Brillouin resolved the paradox by showing the entropy increase made in choosing outweighs the decrease resulting from execution.
Maxwell's demon