"I don't have room for a gigantic pinwheel."

"You don't need a giant pinwheel.  I'm just using them as an example of the thing you're doubting, working.  They powered cities off of those."

"...cool story?" says the jeweler. "Anyway, there's your coil, hope it's as you has in mind, let me know if you need another."

"Will do.  And once I've got a proper heat engine, I'll bring 'round a demo model for you, shall I?"

"Maybe it's less dumb than it sounds, sure."

"Alright, see you around, then!"

Right, now to make another clock for the university, and also assemble an electrical engine!

Which is to say, a magnet on a stick, hooked up to some bicycle pedals.

This will consume quite a lot of time. Her mice have run out of food and water and she hasn't eaten in awhile either.

If 'quite a lot of time' means 'approximately an hours' sculpting and troportation, now that she has proper tooling developed', she supposes it could be that long.

Nonetheless, she can't just let her mice starve.

Ergo, it is time to get food.

In the environs of her storage unit there are carts selling spicy rice with eggs, fried dough full of bean paste, lamb skewers with assorted vegetables, and fresh fruit.

...Can't go wrong with - oh, apparently you can, gleh, icky beans mouthfeel.  ...Can mice eat beans?

Well, she'll grab an apple to take the taste of that off her mind, and head to the library, because speaking of not-starving, she wanted to see if demon mice a) existed and b) worked as a drowsing target.

Mice are apparently willing to eat beans.

Demonic mice don't exist.

What, no-one's tried making one ever?  Especially if demons don't senesce!

Apparently demonicness doesn't transfer.

...But not-starving has been transferred.

No, the urge to eat souls has been transferred. The test subject didn't live very long after attempting to eat some souls.

...And did the demon starve, afterwards?

Nope! It was fine! Demons may just be an infinite font of the desire to eat souls!

...what the fuck is this bullshit.

And nobody tried again, she presumes, because getting zombie in your brain helps no-one.

Still, did anyone do animal testing?  Surely they didn't try humans first!

Yeah, you can make animals try to eat souls too.

And do they still starve?

Yup.

...Well, that suggests there's another trait involved that someone missed.  Were the sources of soul-eating still interested in soul-eating afterwards?

Yup!

...has anyone tried troporting soul-hunger off of something that wasn't...well. they can't actually reproduce, but - something they put soul-hunger on in the first place?

Doesn't work. Soul hunger is very sticky.