No experience, sorry, but only my thoughts of dealing with a different thinker 
I can see his point entirely, he's a scientist doing serious experiments and his ideas are pretty much creative and commendable aside from he's oblivious to the dangers of course.
Do you know anyone who works in science 'doing experiments' who could have a word with him and show him how experiments have to be risk and safety assessed before they are carried out? I'm expecting there must be a standard protocol for using say fire (!).
All he's doing is charging headlong into the actual fun part of experiments without realising there's groundwork to do first. I'm pretty sure if procedures were explained to him by 'the Scientist' or someone he respected, he'd catch on pretty quickly and become an advocate for safe experimenting.
Could he have an Experiment Journal or blog where he outlines all the pre-procedure, maybe even gets that approved by The Scientist and you, then safely does the experiment, then writes up the results?
If this is off the wall, plese ignore it. I hope someone else can offer some suggestions who has delt with similar.