FIG. 16.—A "SPIRIT" PHOTOGRAPH.

Many years ago, in the old wet-collodion days, a well-known photographer was one day surprised by the visitation of a spirit. The apparition did not make its appearance during the nocturnal hours, as is, we have been given to understand, the custom of these ladies and gentlemen from the other world, but, strangely enough, in broad daylight; and not by his bedside to disturb his peaceful slumber, but upon the photograph he was in the act of producing. Had this gentleman been of that soft-brained kind, so easily gulled by the professional spiritualist, it is possible that he would not have done what he did, which was to make a thorough and scientific examination as to the probable cause of the phenomenon. The case was this: A gentleman sitter had been taken in the usual manner upon a collodion plate. Upon taking a positive print from the negative, he was surprised to find a dim white figure of a lady apparently hovering over the unconscious sitter. Upon examination of the negative, the image of the figure was also visible, but not so plainly as in the positive. The explanation of the whole matter was soon discovered. In those days glass was not so cheap as at present, and all old or spoilt negatives were cleaned off and freshly prepared with collodion for further use. In this case the glass had previously supported the negative image of a lady dressed in white. Some chemical action had evidently taken place between the image and the glass itself, turning the latter slightly yellow in some parts. This faint yellow image, although hardly visible in the negative, had, being of a non-actinic color, given quite a distinct image in the positive. The case was not an isolated one, as these spirit photographs, as they were called, often made their appearance when old negatives were cleaned and the glass used again. The precise action producing the image has never, we think, been satisfactorily explained. It could often be made more distinct by breathing on the glass. We do not know if any enterprising humbug ever took advantage of this method of producing spirit photographs to extort money from the unwary, but about ten years ago a work was published, entitled "Chronicles of the Photographs of Spiritual Beings and Phenomena Invisible to the Material Eye," by a Miss Houghton. In this a number of reproductions of photographs of "spirits" were given with a detailed explanation of how they were obtained and the difficulties attending their production, the "spirits" being apparently of very independent natures, only making their appearance when they felt so inclined. It is quite possible that a person entirely ignorant of photographic methods might be led into the belief that they were actually photographic images of the dead, but we fear that the book is hardly well enough written to deceive the experienced photographer. At certain and most unfortunate periods in the process employed, some of the plates had a convenient habit of slipping into the washing tank and there, according to the author, becoming utterly ruined; also we learn that many were ruined by being accidentally smudged by the photographer's finger. We should not, we fear, have a very high opinion of an operator who was in the constant habit of "smudging" negatives with his fingers so as to entirely spoil them, nor can we quite understand what brand of plates was used that "got spoiled by falling into the water."