i3« 



NATURE 



[April 13, 19 16 



wide variation exists in their response to the same 

 exposure. An absence ot chlorophyll makes for 

 increased sensitiveness, and the multi-nucleated 

 forms suffer more than the mono-nucleated, and 

 the large forms more than the small. In the 

 testicle the rays show an essentially selective 

 action, the seminiferous epithelium being- destroyed 

 by a dose to which the cells of Sertoli are in- 

 different. Certain tissues are highly sensitive to 

 the X-rays^ — ^notably lymphoid tissue, cartilage, 

 and the endothelium of blood-vessels. Within 

 limits it is true to say that very rapidly growing 

 cells are most affected by irradiation. But it is 

 important to note that different rays give rise 

 to different efTects upon one and the same kind of 

 cell, and "a careful distinction should be made 

 between the differential action which different 

 rays have upon the same variety of cell, and the 

 selective action which the same kind of radiation 

 has upon the many different varieties of cells." 

 The X-ray spectrum covers a range of many 

 octaves of wave-length. 



If we consider a single cell, we find it exhibits 

 a widely varying degree of^ reaction (to irradia- 

 tion) according to' the particular phase of its life 

 cycle in which it happens to be at the time. Thus 

 certain ova are nearly eight times as vulnerable 

 to j8-rays when they are in an active state of 

 division as when they are in a resting stage. This 

 fact indicates one of the difficulties of quantita- 

 tive investigations upon living tissues. The 

 chemical composition of a cell may determine the 

 degree of change brought about by irradiation. 

 In sections of malignant growths cut for the 

 microscope before and after irradiation, the stain- 

 ing reactions point to marked changes in chemical 

 composition, and these go hand in hand with the 

 morphological changes. 



The authors have given us a book which cannot 

 fail to appeal to the clinical radiologist and to 

 the laboratory worker. Each chapter has received 

 careful study in the writing, and provides food 

 for thought and suggests scope for further in- 

 vestigation on the part of the reader. The book 

 is well printed in clear type on good paper, and 

 contains many excellent illustrations. There is 

 an index of authors, as well as a full general 

 index. 



THE MEDIUM UNDER THE MICROSCOPE. 



A Contribution to the Study of the Psychology of 

 Mrs. Piper's Trance Phenomena. By Mrs. 

 Henry Sidgwick. Proceedings of the Society 

 for Psychical Research. Part Ixxi., vol. xxviii, 

 December, 191 5. Pp. xix + 657. (Glasgow : 

 R. Maclehose and Co., Ltd., 1915.) Price 125. 

 net. 



^liriLLIAM JAMES once referred to Henry 

 * ^ Sidgwick as " the most txasperatingly 

 critical mind in England," and the whimsical com- 

 pliment was well deserved. After the death of the 

 famous professor of moral philosophy, the mantle 

 of the arch-critic fell naturally on the shoulders of 

 one of Sidgwick's most able pupils, Mr. A. J. 



NO. 2424, VOL. 97] 



Balfour, whose " Defence of Philosophic Doubt "" 

 was as destructive as we hope our Navy will be 

 under his First Lordship ; but now that he has 

 reached a more constructive period, as evidenced 

 by his recent "Theism and Humanism," the pal- 

 lium passes to his sister, the professor's widow, 

 and late principal of Newnham College. Anyone 

 who is not willing to believe unquestioningly what 

 has successfully passed the ordeal of her scrutiny 

 must be constitutionally unable to believe any- 

 thing. If she were censor the newspapers would 

 have to cease publication, for she would never 

 believe any but official reports, and probably not 

 them. 



In this bulky volume Mrs. Sidgwick discusses 

 the phenomena of the famous Boston medium who 

 has been for twenty-five years almost continuously 

 under the supervision of various eminent scientific 

 men, including Prof. James — ^who was an M.D, as 

 well as the apostle of Pragmatism— and Sir Oliver 

 Lodge. This lady began to experience sleep-like 

 trances in 1884, but they were only sleep-like so 

 far as concerned Mrs. Piper's normal conscious- 

 ness, for her tongue talked — or, later, her hand 

 wrote— in a very wideawake fashion. What was 

 there, in place of Mrs. Piper's normal conscious- 

 ness, which certainly was not there, furnishes the 

 theme of Mrs. Sidgwick 's discourse. First, osten- 

 sibly, came a Dr. Phinuit, a " spirit " who said he 

 had been a doctor in Metz. Investigation failed 

 to trace his earthly career, and his knowledge of 

 French was scanty — seemed, in fact, about like 

 Mrs. Piper's. But the queer thing was that this 

 dubious entity could usually tell sitters quite a lot 

 about their deceased relatives, and he professed to 

 get the information from the relatives themselves, 

 who were with him in the spiritual realms. This 

 kind of thing happened freely, even when the in- 

 vestigators introduced sitters from a distance — 

 people entirely unknown to Mrs. Piper- — anony- 

 mously or pseudonymously. Then another spirit 

 turned up — George Pelham, a lawyer formerly 

 known to the Society's chief investigator, Dr. 

 Richard Hodgson — who gave any amount of 

 identification evidence about himself, recognising 

 his friends and greeting them by name in aston- 

 ishingly correct fashion. Later there appeared 

 various characters in early history. Lastly 

 came Hodgson, who had died in 1905 ; but his 

 evidence is not very weighty, because he was 

 known to Mrs. Piper, and consequently we must 

 assume that any given would-be identification-fact 

 may also have been known to her. 



Now what about all these "controls " and "com- 

 municators"? W^hat are they, anyhow? Spirits, 

 as they allege, or dream-personalities, fragments 

 of Mrs. Piper's subliminal or hypnotic conscious- 

 ness? Mrs. Sidgwick thinks the latter; and most 

 people will agree with her rather than weigh all 

 her arguments, which are lengthy and compli- 

 cated, though the historical part of the book is 

 easy and interesting. She admits, however, thati 

 Mrs. Piper's trance utterances contain a great 

 deal of matter which Mrs. Piper has not learnt 

 through the known sensory channels. This dis- 



