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

ered as a source of electricity, as says Dc la Eire, as well as influenced by electricity, we may be able all the better to rightly estimate that share of influence in the phenomena that are brought about by the applications of electric currents or shocks, when we also comprehend the work of the natural electric cur- rents which the human organism possesses, and which are insep- arably connected with its healthy functions, as well as its abnor- mal states, and actions. Effects of Heat and Cold on the Ncrvo-Electric Batteries. — It is no uncommon tiling to have the working of a set of com- pound galvanic batteries diminish as much as one half by sudden cold weather, or increase one half in effects of working by a change to very warm air. For this we must be prepared. And of all agents which act upon the human frame, variations in tempera- ture, if sudden and considerable, doubtless produce the most potent results. It is demonstrated that the functions of animal life arc actually voltaic-like ; and it is possible that this view of the exhausting effects of extreme heat, and of the suspension of action from extreme cold, accounts for these familiar facts. Indeed, from actual experiment it is shown that the phenomenon of life is depending upon unceasing native electric currents, and that these arc enormously influenced by heat and cold. Heat first excites ; then, if intense or prolonged, it exhausts the powers of the part or whole of the animal on which it acts. Cold first increases respiration, but a greater degree depresses, then, at last, even to total inaction ; so that there is not only cessation of feeling and of motion, but even of life itself. Vari- ations in temperature act more powerfully than we are apt to think upon the whole electro-nervous apparatus of our organism, and hence affect the cerebro-spinal axis. Thus heat and cold affect pains, delirium, sleep, inflammations, and all those condi- tions and diseases in which the electro-nervous power is mainly concerned. In nervous restlessness or sleeplessness, if cold water is applied over the top of the head, or sponged over the whole body, until some little chilliness is produced, a good sleep will often follow, even where all nervines and narcotics have failed.