The person who is developing mediumship will do well to surround himself with persons of a certain type of psychical power, and to form circles of such persons. Such persons are invaluable in constituting a "developing circle." Such persons need not be mediumistic themselves, nor are they required to actually do anything. Instead, their service is that of being present as psychical reservoirs of force upon which the spirits can draw for manifesting power. The medium, being sensitive to helpful influences, and the reverse, will recognize such persons by the congenial and harmonious influence they exercise upon him; and he will do well to encourage such persons to sit in his developing circles. Impersonating Mediumship. What is known as "impersonating mediumship" occurs where the medium is so completely under the control of the manifesting spirit that he will exhibit, often in a marvelously accurate manner, the personal characteristics and mannerisms of the spirit, and which are readily recognized as such by the spirit's surviving friends in earth-life. Sometimes the medium will actually re-enact the dying moments of the controlling spirit. In many cases such impersonations have been so nearly photographically and phonographically correct that they have afforded the most convincing proof to investigators, and in other cases have been a great consolation to relatives of the spirit who have been thus assured that their loved one was still in actual existence on a higher plane of being. These results, however, are possible only when a very close rapport condition has been established between the spirit and the medium. In cases in which such a close rapport condition is obtained, and a high degree of harmony developed, the spirit will be able to positively establish his identity by causing the medium to utter his exact words, and to give names, dates, and close details of incidents occurring in his earth life, and often to employ his exact set phrases and verbal tricks of speech, so as to bring to the consciousness of the sitters the realization that they are in the actual presence of the decarnate spirit friend. The Proper Mental Condition.