I have a just started a new saga and have a player that is playing a magus who is boardering on scientist. He wants to invent a spell to change water into any other known liquid. My questions are, is this to generic? And how would I go about it? My first idea is
T: Touch +1
D: Sun +2
Base: 25 (change a liquid into a poison that causes a fatal wound)
+1 For generic qulity
This spell can turn water into any liquid that the caster knows of or an acid dealing up to +25 damage.
I don't have a name yet because the magus has yet to have named the spell, much less do I think he will be able to invent it for some time.
Also notice that Muto magic only changes things TEMPORARILY, for a permanent "change" you would need to Perdo the liquid and create a new liquid using a momentary Creo ritual (a combined Creo Aquam spell with a Perdo requisite is an option). True change is beyond the scope of Hermetic magic (specifically, violating the limit of Essential Nature). If the character wants to REALLY change the liquid, he will have to find non-Hermetic ways of doing so. (I'm not aware of any in-cannon way to do so.)
Ah, that may actually be a problem as far as I am concerned. Which is to say I wouldn't allow such a spell to be used to provide bonuses in the laboratory or something like that. That's because the Essential Nature of the liquid hasn't changed, so magically it hasn't changed - while it's color and so on may have changed, it isn't changed in terms of Hermetic Magic Theory. For magical purposes, it hasn't changed at all. (In my opinion, your mileage may vary, and so on...)
In other words, he may change lead to gold temporarily by magic, but when he then utilizes gold's resonance with Rego Mentem magic the magically altered lead will only confuse the results, it won't behave like true gold.
Hermetic magic can not change the essential nature of the liquid but it can't do anything with the essential natue of the subject that the magus is appltying the new found understanding to either. My mileage varies.
(I think that the section concerning applying spells to lab quality in the covenants book is well balanced and I advise using it.)