[9] Unless, of course, there happens to be in the room a source of ultra-violet rays other than the ordinary illuminant by which the photograph is taken but which does not emit visible light rays. This possibility may be disregarded for practical purposes. [10] _Note._--Some believers in spirit photography will dissent from this view on the ground that experiment has shown that when a photograph is taken the extra is not produced by the reflection of ultra-violet light from an “object” (partial materialisation or the like) but by the use of a “psychic transparency” applied to the plate and exposed to “spirit” light. With the first part of this we cordially agree, but the hypothesis of the “psychic transparency” seems to be no more than a resolute attempt to evade the plainest indications of fraud. _Vide infra._--[ED., P.R.Q.] [11] Readers should refer to Mr. E. J. Dingwall’s interesting article on “Magic and Mediumship” in the January number of the _Psychic Research Quarterly_. [12] Cf. pp. 11-12. [13] _Note._--This is a case where recognition _is_ possible because (_a_) the “extra” and the original portrait can be laid side by side and directly compared, (_b_) careful measurements can be made of the facial angle and other characteristics, and (_c_) independent witnesses in any desired number can make the comparison for themselves. [14] Similar observations apply to “The Hunter Test” (_Light_, Feb. _19th_.) [15] _Cf._ p. 30 above. TRANSCRIBER’S NOTES: Italicized text is surrounded by underscores: _italics_. Obvious typographical errors have been corrected. Inconsistencies in hyphenation have been standardized. Archaic or alternate spellings have been retained. End of the Project Gutenberg EBook of The Case Against Spirit Photographs, by C. Vincent Patrick and W. Whately Smith