Ok, I can’t find a good reference for this but… England underwent a fad in Georgian times for applying French language rules to English. I say “fad” but some of these differences are still present today, e.g the pronunciation of “futile” and “fertile”.

And this applies to “h”. For pretty much the whole of the Victorian period “an hallucinated” was considered correct. I know people who still consider it correct, modern style guides be damned.

Eliot, ever the English traditionalist cosplayer, would have treated h as a vowel for these purposes.