Wilson's Theorem/Corollary 2/Historical Note

Historical Note on Generalization of Wilson's Theorem
This generalization of Wilson's theorem was demonstrated, according to, by in $1890$.

It is supposed that this appears in 's $1890$ article during the course of his proof of Stickelberger's Theorem.

However, not only is the latter behind a paywall, it is also in a language the author of this page is not fluent in, and he has been disinclined to study it.