There are undoubtedly vibrations set up in the brain when one thinks, and there are undoubtedly waves of thought just as there are waves of electricity. Science informs us that there is an increase of temperature in the human brain during periods of thought-activity, and also that there are constant chemical changes in the structure going on when the brain cells are active. This is akin to the generation of electricity in a battery, and undoubtedly acts in the same way in producing vibrations, and transmitting them to the brain of another. Sir William Crookes, in the address just quoted, points out the direction of the scientific theories concerning the matter. But, this is all that we shall have to say about the theory of Mind Reading. We shall now pass on to the actual practical instruction. The student is asked, however, to always carry in his mind the fact that Mind travels in waves from one brain to another just as electricity travels from the Transmitter to the Receiver. By holding this picture in your mind, you will have the whole practical theory, in condensed form, right before you, so that you may be able to act accordingly. LESSON II. THE PROOFS OF MIND READING. As we have said in the previous chapter, the general public is gradually awakening to the knowledge of the reality of Mental Transference, and it is scarcely necessary to devote the time and space to a proof of the reality of the phenomena in these days, although a few years ago a work on the subject would have had to be composed principally of evidences and proofs. But, nevertheless, it may be well for us to take a hasty look at the nature of the proof in this work. Nearly everyone has had evidences of Mind Reading or Thought Transference in his or her own life. Nearly every one has had experiences of being in a person's company when one of the two would make a remark and the other, somewhat startled, would exclaim, "Why, that's just what I was going to say," or words to that effect. Nearly every one has had experiences of knowing what a second person was going to say before the person spoke. And, likewise common is the experience of thinking of a person a few moments before the person came into sight. Many of us have suddenly found ourselves thinking of a person who had been out of our minds for months, or years, when all of a sudden the person himself would appear. These instances are so common as to be generally recognized, without question. These occurrences have given rise to the two common "sayings," viz., "Speak of the devil and his imps appear," or "Speak of angels and you hear the rustle of their wings."