But withholding irritation, and securing rest and quiet, do not comprise all the physician’s duty in relation to the mind, any more than they do in relation to the body of the patient. He is sometimes to excite the mind to positive action, for the same reasons that exciting medicines are sometimes administered to the body; and he may thus often exert, through the mind, a very happy influence upon disease. This remedy, as I have already hinted, is to be applied with discretion, according to the nature of each case, and so as not to interfere with that rest, which I have shown to be so necessary to the mind in the treatment of disease. The excitement must, with some few exceptions, be agreeable in character, in order that it may produce a genial influence upon the nervous system. The mode, the time and the degree of its application require the exercise of discrimination, as much as the dose, and form, and time of any stimulant or other medicine that is given to the patient. The judgment and tact of the physician are never more needed than upon such points as these. Tissot, a French physician, relates an amusing case, showing the utility of discrimination in regard to the kind of mental stimulation to be applied. A lady was affected with a lethargy, and many applications were used to rouse her, but to no purpose. At length a person, who knew that the love of money was the ruling passion of her soul, put some French crowns into her hand. After a few minutes she opened her eyes, and was soon entirely aroused from her stupor. The influence of the imagination upon the body is familiar to every one. I will mention a few cases to show its power. Beddoes, an English physician of great enthusiasm, had imbibed, among other new ideas, the notion that palsy could be cured by inhaling nitrous oxide gas. He requested that eminent chemist, Sir Humphrey Davy, to administer the gas to one of his patients, and sent him to him for that purpose. Sir Humphrey put the bulb of a thermometer under the tongue of the paralytic, to ascertain the temperature of the body, so that he might see whether it would be at all affected by the inhalation of the gas. The sick man, filled with faith from the assurances of the ardent Dr. Beddoes, and supposing that the thermometer was the remedy, declared at once that he felt better. Davy, desirous of seeing how much imagination would do in such a case, then told him that enough had been done for that time, and directed him to come the next day. The application of the thermometer was made from day to day in the same way, and in a fortnight the man was cured.