"For the first time within my knowledge", said he, gently, "a nymph has defied me and my laws; yet in my heart can I find no word of chiding. What is your desire, Necile?"
Source: L. Frank Baum: The Life and Adventures of Santa Claus.
I would like to ask whether the inversions in the excerpt above are OK. I mean "said he…" and "yet in my heart can I find…". Maybe it is the result of bad proofreading of my edition…
The answer to whether the inversions are acceptable is yes. You can verify this by asking yourself "what grammatical rule do they break?"
Perhaps more interesting is the question of why the inversions are there. The comments grasp generally that it sounds kind of like poetry. Why is that?
Well, English grammar creates several permutations of word order that are grammatically correct, but typical usage follows a pattern. Disrupting that pattern makes the words sound off. Poetry often disrupts typical word order in order to preserve a poetic meter. Shakespeare, for example, will often do so to let his poetry speaking characters continue to speak in Iambic Pentameter. He wrote the speech that way in order to let the audience know that these characters were noble or 'highbrow' (and also because it is aesthetically pleasing) as opposed to his 'lowbrow' characters who would have unmetered speech patterns.
That means that failing to follow common usage patterns for no particular reason is a bad idea because the odd effect it creates diminishes clarity. On the other hand, if you are willing to accept diminished clarity in order to produce an effect (like poetic meter) that might be a worthwhile trade off.
Interestingly, in your example I can't detect the speaker having a particular poetic meter, so it's likely the case that the inversions are used to invoke the sound of a poetical syntax without actually writing in poetry.
