Others, who have lately discussed the subject, suggest that the douser is affected not by any known kind of physical vibrations, but by some mysterious emanation from the concealed metals or water similar to that which they (without any sufficient evidence) assume to pass from one human being to another over long distances, causing what has been called "second-sight," "thought-reading," and (in order to give an air of scientific importance to it) "telepathy." This may seem satisfactory to some people, but it is plainly a case of attempting to explain a little-known thing by reference to a still less known thing--what is called "ignotum per ignotius." Sir W. F. Barrett, of Dublin, has lately written on this subject, and very rightly says that the real question to be decided in the first instance is whether the modern "water-finders," who profess to be guided by occult influences, whatever the nature of those influences may be, are more successful in discovering water than those who seek for it by the use of the known natural indications of its presence; and, further,--and this seems to me to be the most important consideration,--whether, taking into account all the "experiments" made by the occultist water-finders, both the successful and the unsuccessful, the proportion of successes is greater than might be expected as a matter of chance and the use of common intelligence. That is, in fact, the interesting point about the persistent belief in the "magical" powers of water-finders. It is one of several more or less traditional beliefs which depend on coincidence. The belief in birth-marks is of this nature. A lizard drops from the ceiling of her room on to a woman. A few weeks afterwards she bears a child which has a mark upon its breast more or less "resembling" a lizard. Some people believe that the mark on the child is caused by what is called "a maternal impression," the influence on the mother's mind of the scare caused by the lizard being expressed in the mark on the child's body. To form a conclusion as to the truth of this explanation we require to know what proportion of mothers in a given population have been startled by lizards, what proportion of children are born with marks on them more or less "resembling" a lizard (there is much significance in the "more or less"), and whether there are more children born with a lizard-like mark on the body from mothers who have been frightened shortly before the child's birth by a lizard, than from mothers who have not been thus frightened. The inquiry is not an easy one. The same question of coincidence applies to water-finding. Taking several thousand attempts to find water we must ask, "Is the attempt unsuccessful in a larger percentage of trials in the case of those who do not follow the indications of a dousing-rod than in the case of those who make use of it?" Sir W. F. Barrett admits the difficulty of getting at satisfactory statistics in the matter; but is inclined to