Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

While the patient is sitting in the insulating chair, and charged positively, sparks can be drawn from the body by applying any conductor near to the patient. If the person is being charged negatively, the same manoeuvre will give sparks to the spot where it approximates. In either case there is a vivid flash of light, which, so far as it goes, is a streak of lightning. This is al- ways attended with the sound of a sharp crack, as the negative electricity instantly combines with the positive. The sensation of a spark on the skin is like that of a slight prick of a pin ; and this pricking sensation is in proportion to the length of the spark, as well as according to the sensibility of the part. Hence it is necessary to proceed gently with this by holding the ball of the conductor against the skin, or very close to it, at the commence- ment, until the patient gets a little accustomed to its sensation, when the discharger may be carried farther off to give longer and stronger sparks, and produce a greater effect. Giving sparks does not have so much effect locally as drawing the less frequent but longer sparks ; for this latter produces a local accu- mulation of high-tension electricity in the skin and sub-adjacent tissues near the spot where the ball approaches the body. Here is the simple and most true localization of electricity. This method of applying electricity for the sick has been much em- ployed for many years as the most efficient and reliable remedy for given cases, by Dr. Golding Bird, in the " Electrical Room" of Guy's Hospital. The method there adopted was as follows : A brass ball-tipped director, (discharger,) with an insulating handle, was furnished with an adjustable chain, or large wire conductor, which is put in thorough connection with the ground. This, I find, is more readily done by using a good-sized chain, — say half inch, and silvered, — with a smooth hook on its end, to be readily adjusted on the metal shank of the discharger, and passing the ball of the discharger gradually and wavingly, more or less close, up and down the spine, within about an inch or so of the surface of the body or limb. It is understood that the patient is being retained positively charged by the unceasing action of the machine from friction, that keeps up the supply to the body, which here escapes to the ball and chain, and so to the