Is there a phrase for someone working on a long, tedious scholarly work?

I seem to recall a trope or literary character representing someone working on a dry, boring work of abstruse scholarship. I thought it might be Middlemarch's Casaubon, but I don't think he quite fits the bill (he was actually something of a sham, not having the necessary German...)

The person I have in mind would be an ivory tower academic working on, for example, a ten-volume history of earthworms; not entirely pointless, but totally disconnected from any real-world relevance.

A harmless drudge?

When, in 1755, Johnson published his Dictionary of the English Language, after seven years of solitary toil, he included this definition:

Lexicographer: a writer of dictionaries; a harmless drudge that busies himself in tracing the original and detailing the signification of words