As usual, we find examples of all degrees of the power to see into this memory of nature, from the trained man who can consult the record for himself at will, down to the person who gets nothing but occasional vague glimpses, or has even perhaps had only one such glimpse. But even the man who possesses this faculty only partially and occasionally still finds it of the deepest interest. The psychometer, who needs an object physically connected with the past in order to bring it all into life again around him, and the crystal-gazer who can sometimes direct his less certain astral telescope to some historic scene of long ago, may both derive the greatest enjoyment from the exercise of their respective gifts, even though they may not always understand exactly how their results are produced, and may not have them fully under control under all circumstances. In many cases of the lower manifestations of these powers we find that they are exercised unconsciously; many a crystal-gazer watches scenes from the past without being able to distinguish them from visions of the present, and many a vaguely-psychic person finds pictures constantly arising before his eyes without ever realizing that he is in effect psychometrizing the various objects around him as he happens to touch them or stand near them. An interesting variant of this class of psychics is the man who is able to psychometrize persons only, and not inanimate objects as is more usual. In most cases this faculty shows itself erratically, so that such a psychic will, when introduced to a stranger, often see in a flash some prominent event in that stranger's earlier life, but on other similar occasions will receive no special impression. More rarely we meet with someone who gets detailed visions of the past life of everyone whom he encounters. Perhaps one of the best examples of this class was the German writer Zschokke, who describes in his autobiography this extraordinary power of which he found himself possessed. He says:-- "It has happened to me occasionally at the first meeting with a total stranger, when I have been listening in silence to his conversation, that his past life up to the present moment, with many minute circumstances belonging to one or other particular scene in it, has come across me like a dream, but distinctly, entirely involuntarily and unsought, occupying in duration a few minutes.