I have to consider this a rather dispiriting story:
In 1818, a whale oil dealer refused to pay a fish-product fine on whale oil, because a whale isn’t a fish. The inspector insisted on the tax, and a spirited court and public battle played out.
It’s dispiriting because you’d think the weight of scientific evidence (and if you prefer it, the testimony of no less an authority than Aristotle) would have settled this case easily, but no…the whale lost and was declared a fish.