Why transmutation is not a valid test for the Philsopher Stone ?
In Hermetism there is the science of Archemy, that deals partly with the transmutatory matters, and "particulars" able to make sometime, powerful transmutation powders, looking like a Powder from a Stone, and making the same effect on lead or any metal (and making of gold a red glass, etc).
Now, gold is said to be different after a transmutation by a Stone (harder, not attacked by acids...). But one can perfectly change the nature of a metal by adding too much of this or that, and to make it very hard or brittle or glowing red instead of green while melted. Depending of the "cooking" !
So, in this case, there is only the very high potential of transmutation of a tiny peice of Powder, from a Stone that could possibly make the difference, but how can we be sure that it is safe as a medicine ?
Sometime a Stone cannot transmute by itself, you need to know Archemy in order to make it a Powder (sometime it is not the case). It can perfectly fail the transmutation, and being a Stone.
Why making a test of transmutation if we seek a spiritual and physical remedy ? In this case, why don't we try the Stone upon an old and ill animal ? Making a healing, and a regeneration maybe. This could be a proof. A real proof. Not like a transmutation made with Archemical procedures with a Stone. And a metal do not die or present illness after being exposed to a high level of toxic material. How to be sure it is safe ?
It is said that the Stone makes an evolution. Yes of course, as a remedy, it makes things perfect. But an animal regenerated will not be transform as a human baby, and a nettle will not transform in a rose tree. There is not change in the form, only in the quality, it is not a trans-formation, it is a mutation.