In Fig. 3 the patient is being “charged” with _positive_ electricity, or, as the electro-therapeutists of fifty years ago would have said, “he is taking an electro-positive bath,” by being insulated and connected through the metallic rod held in his hand with the accumulator upon which the positive electricity is stored, while the negative electricity is “run off” by a brass chain leading from the negative accumulator to the ground. If the process were reversed, the positive accumulator, being connected with the ground, and the patient with the negative one seen at the top of the machine, he would be taking “an electro-negative bath;” for we make him, as it were, a part of each accumulator as the case may be; its accumulated electricity passes to him and he becomes _charged_. If the air were perfectly dry he would continue (as he is insulated) in this charged condition, but owing to its contained moisture the electricity rapidly leaves him, and to maintain the charge it is necessary that the plate of the machine should be kept in constant rotation. Indeed, the escape of electricity is so rapid that to get the best action we must have a fire in the room, and before use well rub the plate, the insulating supports, the legs of the stool, and all the glass parts of the apparatus with a warm and dry piece of flannel. This is of importance, and however dry the day, should as a rule never be neglected. By smearing the inside of the cushions of the machine with a little paste, composed of an alloy of mercury and tin (technically known as “amalgam”), mixed with a little tallow, the amount of electricity is much increased, but care should be taken not to smear the cushions with too much, which had better be bought ready prepared. A piece about the size of a small grape for each of the cushions will be enough, and no more need be added for two or three weeks. Always scrape off old amalgam before adding new. The cushions should be screwed sufficiently tight to slightly “grip” the plate, and if it is found that notwithstanding having rubbed the glass of the apparatus as above directed, the instrument is not supplying a sufficient quantity of electricity, remove the cushions and warm them thoroughly. _It is impossible to be too careful that everything is warm, clean, and dry_, for the great obstacle that exists against the extended use of Franklinism is found in this difficulty sometimes present, from neglect of the above precautions, in getting efficient action. But even on a foggy day the instrument, _with proper care_, may be made to act well. The operator should also remember that dust must be sedulously guarded against. A few drops of petroleum may be sprinkled upon the table, and their vapour condensing upon the machine will aid in protecting it against moisture.[5]