It is a brush discharge, which is interesting in more than one respect.
brush discharge, or anything that electrifies the air itself, is the most expeditious.
The plates are placed in a vessel full of insulating oil which prevents the glow or brush discharge taking place over their edges.
In the latter case a brush discharge is used, and the patient experiences very little physical sensation.
In the use of alternating currents of very high tension, too much precaution cannot be taken to prevent the brush discharge.
There is still another and far more striking peculiarity of the brush discharge produced by very rapidly alternating currents.
It is, in fact, the equivalent in nature of the brush discharge from an electric machine.
This is caused by the electricity escaping into the air from the point of the needle, and is known as the “brush discharge.”