The Long s

This is what happens when a computer e-text program scans an "f" as an "s" and vice versa:

And again he flew out of the house, leaving Dr. Lyster unassectedly concerned for him, and too kind-hearted and too wife to be offended at the injustice of immoderate sorrow.

Which should read:
And again he flew out of the house, leaving Dr. Lyster unaffectedly concerned for him, and too kind-hearted and too wise to be offended at the injustice of immoderate sorrow.

And there's also this:

"My name, fir?"

This humorous example is a result of old typeface where the lowercase letter 's' (ſ) resembled the letter 'f'. The letter is specifically known as the Long s.

I can't really fault anyone at the Chadwyck Nineteenth-Century Fiction database for not wanting to proofread Cecilia. It is, after all, over 950 pages long. That said, you can spell an e-text.