This is one of the simplest forms of thought-transference; it is, of course, liable to many errors, and is useless as a scientific test. Bishop, Cumberland, and other mind readers who have exhibited their remarkable powers all over the world, were doubtless sensitives who possessed this power of perception or receiving impressions in a high degree, so that minute objects, such as an ordinary watch-key, hidden in a barrel of rubbish in a cellar and in a distant part of an unfamiliar city, is quickly found, the sensitive being connected with the agent by the slightest contact, or perhaps only by a string or wire. The question at issue in all these cases is the same, namely, do the sensitives receive their impressions regarding what they have to do from the mind of the agent by some process other than the ordinary means of communication, such as seeing, hearing, or touch; or do they, by the exceeding delicacy of their perception, receive impressions from slight indications unintentionally and unconsciously conveyed to them by the agent through the slight contact which is kept up between them? The opinion of a majority of scientific persons has been altogether averse to the theory of thought-transference from one mind to another without the aid of the senses and the ordinary means of communication; and they have maintained that intimations of the thing to be done by the sensitive were conveyed by slight muscular movements unconsciously made by the agent and perhaps unconsciously received by the sensitive. To explain, or rather to formulate these cases, Dr. William B. Carpenter, the eminent English physiologist, proposed the theory of "unconscious muscular action" on the part of the agent and "unconscious cerebration" on the part of the sensitive; and his treatment of the whole subject in his "Mental Physiology," which was published twenty years ago, and also in his book on "Mesmerism and Spiritualism," was thought by many to be conclusive against the theory of mind-reading or thought-transference. Especially was this view entertained by the more conservative portion of the various scientific bodies interested in the subject, and also by that large class of people, scientific and otherwise, who save themselves much trouble by taking their opinions ready made.