Electricity, is the power of attracting light substances, etc„ when excited by heat, or friction : and which may be communicated to other bodies - This term also im-pies that branch of natural philosophy which investigates the nature and effects of this power, and of other elementary agents connected With it.

The science of electricity has made a most rapid progress within the last fifty years; it was little attended to previous to the year 1600, since which period it has been car-to a considerable degree of per-fection. - It would be -transgressing our limits to enter into the history of this subject, as few can be ignorant of the names of Newton, Grey, De Fay, Priestley, Franklin, and Cavallo : farther, as the theory is too diffuse, and requires the aid of too many experiments and analytical expla-nations, we shall confine our a count to medical electricity. This has often been successfully employed for relieving the human frame from painful maladies, though it has till lately been treated as an empirical process. Being one of the most powerful stimulants, its ef-fects may be considered both as general and local. When the vital principle is in a manner extinguished by tooviolentshocks.itmay again be kindled or excited by such as are less powerful. Hence electricity promotes a free circulation of the fluids, and particularly the blood; increases animal heat, perspiration, as well as all the secretions and excretions of the body.

As many professional electricians are little concerned about the propriety or safety of this potent remedy, when patients apply to them, as candidates for the operation, we think it our duty to give the following practical hints: 1. Electricity is always improper in active, inflammatory, or sthenic diseases : 2. It is also hurtful when a high degree of excitement is felt in the organs of sense, as well as in those of voluntary motion, when both are accompanied with relaxation or debility : 3. If any local irritation prevail in the body, such as ulcers, inflammatory tumors, eruptions of the skin, etc. In these cases, the electric stimulus has a direct tendency to produce congestions, or a local accumulation of humours. It has, however, sometimes been found highly beneficial in removing the periodical obstructions of females, though its application requires great precaution. In passive, chronical, or asthenic disorders, it has likewise been of considerable service ; but the mode of imparting the electric fluid deserves more attention than has, in general, hitherto, been bestowed upon it; and violent shocks, for the sake of experiment, ought never to be communicated, where less powerful ones might be sufficient. Tints, the electric lath, and the gentle application of sparks to any particular part of the body, under the conditions before stated, are equally safe, and advantageous. On the contrary, the more violent methods of electrifying have so often been attended with mischievous effects, that they .ought, to be applied to those persons only, whose capacity of receiving external impressions is diminished, and,whose excitability is in a languid state.

Deafness, paralysis, head, and tooth-achs, however obstinate, have frequently yielded to the powerful effects of electricity. Similar success has attended its application to parts affected with the cramp, gouty and rheumatic pains, palsy, and sometimes even epilepsy; besides which, moderate electric shocks have, in various instances, contributed to the resuscitation of persons whose vital functions were destroyed by drowning : it ought, nevertheless, to be resorted to only in particular cases, and under the immediate inspection of a medical practitioner.

For an account of the different medical apparatus employed, and the various modes of electrifying, we refer the curious reader to the late Mr, Adams's "Essays on Electricity and Magnetism," (8vo, 9s.) He will also find much valuable information in Dr. PRiest-ley's "History of Electricity" (4to. 1775, or 2 vols. 8vo. ll. 1s.) and in Mr. Cavallo's "Treatise on Electricity," 3 vols. 8vo. 18s.,