Clairvoyance is the power to see what is hidden from ordinary physical sight. It will be as well to premise that it is very frequently (though by no means always) accompanied by what is called clairaudience, or the power to hear what would be inaudible to the ordinary physical ear. What is written in this little treatise is the result of much careful study and experiment by the author, and that though some of the powers which he describes may seem new and wonderful, he mentions no single one of which he has not myself seen examples.