What year did Paul N. Kree create the multiple probe technique for galvanic electrolysis?

Paul N. Kree developed the multiple probe technique for galvanic electrolysis in 1916. This technique was significant in advancing the field of electrolysis, particularly in its application for hair removal and other aesthetic procedures. The multiple probe technique allowed for more efficient treatments by enabling the use of multiple electrodes simultaneously, which significantly improved the efficacy of galvanic electrolysis. Understanding the timing of this innovation is important as it highlights Kree's contributions to the evolution of electrolysis technology during the early 20th century, a period marked by advancements in medical and cosmetic treatments.