What undesirable effect can result from connecting the positive electrode to the probe instead of the negative electrode during electrolysis?

Connecting the positive electrode to the probe instead of the negative electrode during electrolysis can lead to tattooing. This phenomenon occurs because the process of electrolysis relies on the correct polarity to effectively damage and destroy hair follicles. When the positive electrode is incorrectly connected, it can cause the electrolysis current to create a burning effect on the skin, which may deposit pigment or cause the skin to react in a way that leaves behind marks similar to tattoos.

Tattooing is particularly undesirable because it signifies that the treatment has not only been ineffective in permanently removing hair but has also created an unintended cosmetic concern. Thus, understanding the importance of electrode connectivity is crucial in performing electrolysis safely and effectively, emphasizing the need for proper training and adherence to protocols.