December 9, 1920] 



NATURE 



471 



give an idea of the scope. The photograph herewith 

 shows the ring system when a residual aberration, in 

 the sense of "over-correction," of o^A is present at 

 the best focus, and when the reference plane is taken 

 sufficiently far outside the focus to make the path- 

 difference (i^=i-8A. The small central concentration 

 and the persistent individuality of the interference 

 rings are shown. The first "broad" diffraction ring 

 is now formed through the low intensity of the first 

 bright interference ring. The whole of the above 

 work relates to nearly monochromatic light only. 



A good many of the broad features of these aberra- 

 tion and "out of focus" effects can be explained 

 without difficulty on the basis of the FresncI zone 

 theory, and it is hoped to include a short discussion 

 of this kind in the paper. No more need be said at 

 present except to direct the attention of 'the readers 

 of Naturk to the importance of the paper on " Star 

 Discs " to which the reference is given. 



L. C. Martin. 



Imperial College of Science and Technology, 

 November 25. 



"Phenomena of Materialisation." 



In Nature of November 18 I find what purports 

 to be a review of Dr. von Schrenck-Notzing's work 

 translated by me under the above title. I have always 

 supposed that a reviewer should tell the reader what 

 the book is about. The review in question is headed 

 ■•Th« Newer Spiritualism," and begins : "Of making 

 many books' on spiritualism 'there is no end.'" It 

 states that the phenomena are alleged to have "a 

 spiritistic interpretation," and refers to " the 

 numerous photographs of her (the medium] sand- 

 wiched between faked spirit photographs." All this 

 is thoroughly misleading. The book is not about 

 spiritualism. Both the author (p. 30) and the trans- 

 lator (p. x) discard the "spirit hypothesis" as un- 

 necessary. The author says that " it impedes and 

 hinders in every way serious scientific investigation." 

 The book contains no portrait of the medium, and 

 not a single "spirit photograph," faketl or otherwise. 

 The photographs reproduced have not been mani- 

 pulated in any way except Nos. 127, 128, 134, 136, 

 138, and 140, in which, for purposes of publication, 

 the sex characteristics have been obliterated. These 

 six photographs are marked "retouched," and the 

 reason for retouching is stated in the text. 



The review abounds with other inaccuracies. A 

 red light, was not always employed (see p. 50^. 

 Mme. Bisson did not "hop in and out " of the cabmet. 

 The rare occasions on which she cnterctl it are 

 stated, as ore all the other conditions, with what the 

 reviewer calls "dreary uniformitv," but with what 

 the ordinary scientific reader would call conscientious 

 accuracy. 



The reviewer's challenge to " exhibit " the pheno- 

 mena in London before well-known hostile critics is 

 about as reasonable a^ to ask a performing mouse to 



exhibit its tricks before an audience of hungry cats. 

 The psychological element would probably produce 

 similar inhibitions in both cases. The phenomena are 

 nearly as rare as the fall of a meteorite from the sky, 

 and nearly as spontaneous as the production of bio- . 

 logical "sports." They cannot, therefore, be pro- 

 duced before a massed audience. It is useless to 

 think that any living individual is eminent enough to 

 carry a general conviction of the reality of the pheno- 

 mena, even though he be personally convinced. The 

 only resource is to take the phenomena as and when 

 they come, to record them carefully, if possible by 

 photography and other instrumental means, and to 

 make the experirtiental conditions gradually more 

 rigid until w-e can only conclude that we are face to 

 face with a new set of biological phenomena exhibit- 

 ing the known powers of the human organism in an 

 intensified and much accelerated form. .Vnd this is 

 precisely what Dr. von .Schrenck-Notzing has done. 



E. v.. FOVRNIER n'.\LBE. 



It will be well to de.il with Dr. Fournier d'.AIbe's 

 charges against my accuracy ser'iaiim : 



(i) "Both the author (p. 30) and the translator 

 (p. x) discard the ' spirit hypothesis ' as unnecessary." 

 1 might have made this clearer, but the repudiation 

 is not easy to reconcile with the contents of a book 

 crammed with references to occult phenomena, as, 

 e.g., mediumistic, psychic, aiid telekinetic. 



(2) "The book contains no portraits of the medium, 

 and not a single ' spirit photograph. ' " This is an 

 amazing statement. There are 225 illustrations. Of 

 these there are 13 " drawings," so-called ; all the rest 

 arc flashlight photographs of the medium (if not, then 

 of whom ?) in various attitudes, a large number 

 showing the teleplasma issuing from her mouth, etc. 

 There are 20 flashlight photographs — " phantasms " 

 they arc calle<l — of dead and living people, .\mong 

 the former Mme. Bisson recognised the features of a 

 deceased nephew, Georges Thurner, and also of licr 

 husband, who died in 1912. 



(3) " .\ red light was not always employed (see 

 p. 306)." "All the sittings took place in a red light, 

 so that during the four years there was not a single 

 dark stance" (p. 21). The translator may be left 

 to reconcile this statement with the exception to which 

 he gives the reference. 



(4) " Mme. Bisson did not ' hop in and out ' of 

 the cabinet." Probably she neither hopped nor 

 skipped, but her visits to the cabinet were frequent 

 enough to arouse suspicion as to collusion with a 

 medium over whom she had "absolute control" 

 (p. 59). Dr. Fournier d'.Mbe does not appear to have 

 been present at the sittings. 



(5) "The reviewer's challenge" cannot be accepted 

 because the phenomena cannot " bi' produced before 

 a mixed audience. . . ." " We are face to face with a 

 new set of biological phenomena." .So long as those who 

 assert their belief in leleplaslic exudations from the 

 bcxly and in the genuineness of photographs of the 

 dead refuse to submit tliese "new biological" pheno- 

 mena to the conjoint judgment of men of science and 

 conjurers, they must not be surprised that their so- 

 called " evidence " carries no weight save among the 

 credulous. The Rkviewfr. 



NO. 2667, VOL. 106] 



Higher Forestry Education for the Empire. 

 \ coRREspospKNT has Sent us some remarks upon 

 Prof. .Sfebbing's letter dealing with forestry educa- 

 tion in Natirr of Decemlwr 2, but he has omitted to 

 give his full name and address. No use can, there- 

 fore, be made of his communication. — Editor, 

 Nati;r«. 



