Mental Influence on Organs.--_The Heart_.--The influence of mind can be noted on practically every organ of the body in a concrete way. It might be thought that the heart, the first living thing in the animal being, the pulsations of which begin before there is any sign of the nervous system, might be free from this influence. On the contrary, the heart is so readily affected by mental states that, taking effect for cause, the old popular, and even scientific idea with regard to it, was that it was the organ of the emotions. The heart is stimulated more by favoring circumstances, and suffers more from depression, than almost any other organ. In the melancholic states it usually beats less frequently and is sluggish. When individuals are tired out and the heart has become weakened in its action, new courage will first be noted as having its effect upon the heart action. As the whole muscular system is much influenced by the mental state and, as the control of the arterial system depends on the muscles in the arteries, it is easy to understand how much the general bodily condition may by mental influence be modified for good and ill. _Digestive Tract_.--The stomach and intestines, though their functions might be presumed to be dependent entirely on physical conditions, are almost completely under the control of the mental state. At moments of depression, just after bad news has been received, the appetite is absent, or is very slight and digestion itself proceeds slowly and unsatisfactorily. On the other hand, when there is mental good feeling appetite is vigorous and digestion is usually quite capable of disposing of all that is eaten. If after a period of rejoicing in the midst of which food is taken abundantly bad news is brought, the mental influence on digestion can be seen very well. It is not alone that depression interferes with digestive processes, but apparently some favorable factors for digestion consequent upon the previous state of mind are withdrawn, and now what would have been a proper amount of food proves to be an excess and the digestive organs find it difficult to deal with it..