Cold fire

Question :if we wanted to create fire that burns but that doesn't emit heat,what would be the ingredients?

CrIg +1 mag.

CrIg(Pe)

CrIg(Mu)

PeIg has a spell that renders a fire cold but that still burns so the effect is possible

W

Create your fire via CrIg as normal. Then follow the rules for requisites. As you noted there is a PeIg spell that makes a fire cold, so it seems like a Perdo requisite would handle the lack of heat. So now you have Cr(Pe)Ig, and that will entirely handle the effect. (I would not suggest Muto because then you're letting MuIg take over half of what PeIg does.) Next you need to decide if this is a significant change to the spell or if it's essentially cosmetic. I would say it's more than cosmetic but doesn't make the spell a lot more powerful, ruling it as +1 magnitude. So I would end up with Cr(Pe)Ig at +1 magnitude above the equivalent CrIg spell.

Chris

A muto Ignem version -Boreal flames- is on page 111 of Magi of Hermes