And Sadde drops water from the prism to the egg and tries cracking it to see what he got. "By the way, there's an implication there from what Slughorn said to our little project."

"Oh?"

Upon cracking the egg, quite a lot of blue paint starts leaking from it, and Sadde tries to find a place he can deposit an eggful of paint without making a big(ger) mess. Upon doing so he finishes cracking it and a much tinier blue glass egg falls from it. The glass is itself tinted and not painted. "Huh. This is actually pretty neat." He looks up at Miranda again. "Anyway, apparently the metaphor thing is kinda personal so it's very possible that in addition to finding something meaningful you have to be the kind of person that would produce something?"

"Right. But there's no obvious way to find out, and there's different ways to make stuff, so it might be that anybody can make anything if they find the right set of steps."

"Yeah, no, I'm taking that as encouragement, it's another piece of the 'how come no one else ever managed to do it' puzzle that makes it easier to understand while simultaneously not making our attempt doomed from the start."

"Wait, really? Can I try other things too?"

"Minor variants on procedures you have tried in class only, which I can verify are safe in less than a minute," Slughorn hastens to clarify.

"Oh. Yeah okay I guess. Oh, and we had a couple of questions!"

"Yes, Mr. Woods?"

"So the first thing is, how exactly does this metaphor part work? Like, is it a personal metaphor or some sort of consensus amongst everyone or some combination?"

"It seems likeliest to be a combination, although for obvious reasons it's difficult to examine directly."

"Does learning new things affect it on the same level waiting a few decades does? Like, suppose someone wanted to use a plastic model of an atom for something, but then they learn that in fact that model resembles an atom no more than a chihuahua does, would that change anything?"

"...Not knowing what a plastic model of an atom might be, I can't comment on the example, but all the examples I know of involved decades of interim between attempts. I've never heard of an alchemic ritual in more continuous use by a practitioner changing."

"Filed under things-to-test, then, somehow. Also what about wands? Can they be used as part of the metaphor? Can they be transformed?"

"I think some alchemists have experimented with the use of wands but can't off the top of my head recall any successful attested rituals known to involve them."

"Are they likely to be more dangerous than other rituals, or something?"

"Possibly. Wands can behave unpredictably, especially when used by people not attuned to them - and most people would not choose to give up their wand - or when destroyed."

"What kinds of safety precautions should we take when actually experimenting with this, which will of course only happen after at least the full two years this course lasts and we're not about to go trying it every other weekend?"

Sigh. "Perhaps I should tell you in two years."

"But then if we do end up being insane enough to try it before the two years are up, we won't actually know what to do and may end up exploding much more things than were strictly necessary."

Heavy mustache-ruffling sigh. "Well, if you were thusly insane, you would at least be advised to make sure the wand is never pointed at anything you don't wish exploded, or near anything you don't wish exploded, and does not begin the ritual damaged in any core-exposing way."

He writes this all down, grinning. "Are there any other general precautions for alchemical experimentation? We really aren't gonna experiment anytime soon, but knowing things in advance tends to be useful."