Very few copies of Mumler’s photographs still exist; they are all similar in their general characters to the first. Noteworthy points are that the spirits are always without legs, and are usually on the right of the sitter. A considerable number of his extras, indistinct though they were, were recognised by the sitters and their friends as the dead person whose photograph they were expecting. (The value of these recognitions is dealt with in a later section.) Naturally, cries of fraud were raised, and investigators, consisting of men of science and newspaper representatives, devised “test conditions” to eliminate this possibility. This they did to their own satisfaction, and obtained spirit extras; but on reading their accounts it is easy to see that ample loopholes were left for fraud. In some cases the camera and lens were minutely inspected, and Mumler’s operations carefully supervised, but a glass plate provided by Mumler was used for the sensitised emulsion. (How this renders a natural explanation of the extra possible is explained in the section on methods of fraud.) In other cases where tests were instituted the developing-room was in complete darkness, no ruby light being used, which put the investigators completely in the medium’s hands. On one occasion Mumler was persuaded to forsake his studio for the private house of an investigator. Here he was not allowed to use any of his own apparatus--camera, plates, and chemicals all being provided for him. The result was a complete failure to get anything abnormal on the plates. Mumler explained that he “thought his (medium’s) influence had not been sufficiently long in contact with the chemicals.” This one can readily believe. He presently became bolder, and his spirits’ features became more distinct. This led to a bad mistake, for in February 1863 the sceptics were able to show that one of Mumler’s spirit extras was the likeness of a man still alive, and living in Boston; and, worse still, that this man had had his photograph taken by Mumler a few weeks before. Such carelessness on the part of the spirits ruined a promising business, for after the outcry which followed we hear no more of Mumler for some six years.