authorize your patient to have treatment carried out at home impress this rule upon whosoever electrizes him. Under such circumstances it is especially imperative, for there is great belief, even with educated persons who ought to know better, that the benefit derived from electrization is in exact proportion to the pain given by it, and a little personal experience is a very wholesome corrective to such a notion. Graduate your dose, then, by the number of cells employed checked by testing its effect, and do this upon each application, for there is no certain means of securing that the strength of either a Voltaic or a Faradaic current shall not have varied from day to day. We have now studied, Gentlemen, medical electricity, electrical instruments, and methods of application. In our next and concluding Lecture I propose to discuss the assistance that electricity affords us in diagnosis, prognosis, and treatment. FOOTNOTES: [10] See pages 6-17. [11] See Duchenne (de Boulogne) “On Localized Electrization and its Applications to Pathology and Therapeutics” (English Edition). Part I., pp. 38-40. London: Churchill. [12] It is often of imperative importance in the administration of the “constant” current that we should really localize it--not in name only, but in fact--in some special nerve; and this is not always quite so easy in practice as in theory. [SN: Importance of exactitude in administering a constant current.] To secure the result we desire, we must see that the cord or wire from the terminals of the battery to the electrodes is without flaw; that the electrodes are well moistened and placed firmly in the position determined upon; and especially that they are held quite immovable during the entire application, for if not maintained immovable, we shall be using not a “constant” but an “interrupted” current with totally dissimiliar physiological and therapeutical effects! We must satisfy ourselves that the current from our battery is also constant, and that we so apply it to our patients that the affected nerve shall be--as it is called--included in the circuit--that is, between the poles, and that the current circulates through this nerve as perfectly and continuously as it would through a piece of wire connecting the terminals of the battery. [13] Published by Churchill. LECTURE III. ELECTRICITY IN DIAGNOSIS AND TREATMENT. A.--_Electricity in Diagnosis._ GENTLEMEN, [SN: Electro-Diagnosis.] Our first two Lectures were devoted to a consideration of electrical instruments; the different varieties of electricity; and the most approved methods of applying them in therapeutics. To-day we have to study their uses in diagnosis, prognosis, and treatment. [SN: Test of Electro-Irritability.]