What experiment did Nils Wallerius perform to prove the law?

Nils Wallerius was a Swedish chemist and mineralogist who did important work in the 18th century, but he is not known for any specific experiment to prove a specific law.

It's possible you're thinking of a different scientist, or you've misremembered the details. Could you please provide more information about the law you are interested in, or perhaps clarify the scientist's name?