But the medical faculty have too widely employed electricity in the treatment of disease, and that with too frequent success, to admit of its being denied a place among important therapeutic agents by any respectable practitioner. The only questions concerning it now are those which relate to the _versatility_ of its power, the _scope_ of its useful applicability, and the _principles_ which should guide in the administration of it. The general subject embraced in these questions is one in which suffering humanity has a right to claim that physicians shall be at home. And yet it will scarcely be denied that, in the exhibition of electricity, more than of almost any other therapeutic agent, medical practitioners feel incertitude as to what shall be its effect. Now and then it acts as they expected it to do; sometimes it pleasantly surprises them; oftener it offensively disappoints them. They find it _unreliable_. Of other remedial agents, they commonly know, before administering them, what _sort_ of effect will be produced; but in employing this, while they have hope, they are generally more or less in doubt. They regard it as _a stimulant_; although its action on the living organism appears to them to be largely veiled in mystery. In many cases of disease, particularly those of acutely inflammatory or febrile character, they judge it to be not at all indicated. To administer it in a case of bilious or typhoid fever, or in a case of pneumonia, pleuritis, gastritis, inflammatory rheumatism, or acute, and especially _epidemic_ or malignant dysentery, or in a case of pulmonary phthisis, would probably be viewed by the most of physicians as the rashest empiricism, if not the next thing to madness. _The idea of producing antagonistic effects with it at will_, they would, for the most part, esteem preposterous. Rather, perhaps, it may be said of the majority of medical practitioners that such an idea has never entered their minds; so foreign is it to their conceptions of truth and propriety. But, at whatever risk of discredit or censure, the writer of the present volume avers that this idea is both scientifically sound and of every day's practical verification. The various and opposite forms of disease--acute and chronic, hypersthenic and asthenic--are habitually treated and _cured_, in his own practice and that of his students, by electricity alone. But "_cui bono?_" may be asked. "What if it be true that these things can be done with electricity? They are also done with medicines, which are more quickly and conveniently administered, and usually less annoying to the patient. What, therefore, is the _practical utility_ of your electric system above the ordinary practice, especially if we include, in the latter, electrical treatment as occasionally employed by the most of respectable physicians?" This is the important question--that to which the author desires to call particular attention. He, therefore, answers: