Very probably the most striking expression of the influence of mind upon body is in that wonderful old book, Johann Mueller's text-book of physiology, issued in an English edition (London, 1842) under the title "Elements of Physiology." The subject, a favorite study, is set forth very clearly, and evidently from personal knowledge. He recognized that the mind might influence every organ and function of the body. The influence of expectancy he emphasized particularly: The influence of ideas upon the body gives rise to a very great variety of phenomena which border on the marvelous. It may be stated as a general fact that any state of the body, which is conceived to be approaching and which is expected with perfect confidence and certainty of its occurrence, will be very prone to ensue as the mere result of that idea, if it do not lie without the bounds of possibility. The case mentioned by Pictet, in his observations on nitrous oxide, may be adduced as an illustration of such phenomena. A young lady, Miss B., wished to inspire this intoxicating gas; but in order to test the power of the imagination, common atmospheric air was given to her, instead of the nitrous oxide. She had scarcely taken two or three inspirations of it, when she fell into a state of syncope, which she had never suffered previously; she soon recovered. The influence of the ideas, when they are combined with a state of emotion, generally extends in all directions, affecting the senses, motions and secretions. But even simple ideas, unattended with a disturbed state of the passions, produce most marked organic effects in the body. With regard to the influence of the mind over the body in the matter of fatigue Mueller is especially emphatic. He states just as clearly two generations ago the Law of Reserve Energy as James stated it in recent years. Of course, Mueller was far beyond his time in everything, but then men who really think always are, and even Mueller's accurate expression only represents what had been in the minds of thinking men in many previous generations. He says: The idea of our own strength gives added strength to our movements. A person who is confident of effecting anything by muscular efforts, will do it more easily than one not so confident in his own power. The idea that a change is certainly about to take place in the actions of the nervous system, may produce such a change in the nervous energy, that exertions hitherto impossible become possible. This is still more likely to be the case, if the individual is at the time in a state of mental emotion. Even this necessarily fragmentary and rather disjointed sketch of the main features of psychotherapeutics, as we see them recognized by the great {19} physicians of the past, serve to show that mental influence has always been appreciated as an important element in the care of the individual patient.