NATURE 



THURSDAY, JANUARY 30, 190S. 



THE FUNCTION OF THE STAPES. 



On the Impulses of Compound Sound Waves and 

 their Mechanical Transmission through the Ear. 

 Bv Sir Thomas Wrightson, Bart. Pp. 40, and port- 

 folio of diagrams. (London : Thomas Kcll and Son, 

 1907.) 



LITTLE has been added to our knowledge of the 

 auditory ossicles since the classical researches 

 of Helmholtz, although the subject is of much in- 

 terest. Sir Thomas Wrightson shows that, owing to 

 the peculiar arrangement of the footplate of the 

 stapes and the formation of the annular mem- 

 brane, to and fro movements of the stapes 

 are accompanied by vigorous transverse vibra- 

 tions of its frame. These movements will be repre- 

 sented in any compound wave form by the points at 

 which " the compound curve cuts across the average 

 line representing the central or normal position of the 

 membrane." 



With the help of a very ingenious model, evidence 

 is adduced that this complex of motions affords a 

 reasonable basis for the analysis of compound notes, 

 which is usually attributed to the fibres of the basilar 

 membrane. Careful examination of the numerous 

 wave forms reproduced by the author will, we think, 

 make it clear that the theory advocated is worthy of 

 attention. Sir Thomas Wrightson's criticism of the 

 theory associated with the name of Helmholtz is not, 

 however, entirely just. The statement that " In fact 

 there is no intelligible explanation furnished by Helm- 

 holtz 's theory why we can hear each note of a com- 

 bination when all the component notes are sounded 

 together " can be made with respect to any theory 

 whatever. The real value of the hypothesis of Helm- 

 holtz is that it describes, not explains, a large series 

 of phenomena which cannot easily be reconciled with 

 rival theories. It remains to be seen whether Sir 

 Thomas Wriphtson's theory will better describe the 

 facts. For example, the peculiar condition described 

 bv Jacobson under the name Diplacusis binauralis 

 dvsharmonica, in which the same note heard by the 

 two ears simultaneously produces a dissonance, is 

 most easily described by a theory of resonators in the 

 cochlea. .Again, if it be true that ossification of the 

 fenestra ovalis is consistent with a partial preserva- 

 tion of hearing, as asserted by K. Schaefer (appar- 

 ently on the authority of Frutiger), the function of 

 the stapes would seem to be relatively unimportant ; 

 but evidence on this point is conflicting. The author 

 assumes that an impulse is always imparted to the 

 menibrana basilaris by friction of the perilymph on 

 its under surface ; this is not necessarily the case. As 

 Schaefer remarks : — 



" It is conceivable that the fluid of the labyrinth, 

 receding before the pressure of the stapes, flows from 

 ''-e Scala Vestibuli through the Helicotreme into the 

 Scala Tympani, and converselv when rarefaction 



NO. T996, VOL. 77] 



occurs in the auditory passage. But there is no time 

 for this during the rapid sound vibrations, and it is 

 tar more probable that the membranous partition of 

 the Cochlea bulges towards the Scala Tympani when 

 the stapes moves inwards." 



Whatever position may ultimately be assigned to 

 the theory of stapedial analysis. Sir Thomas Wright- 

 son and Dr. Arthur Keith, who is responsible for 

 the anatomical part of the work, are to be con- 

 gratulated on the performance of an interesting re- 

 search which throws much light on the mode of 

 action of a structure not readily accessible to the 

 physiologist. M. G. 



LIFE AND DEATH. 



The Prolongation of Life. By Elie Metchnikoff. The 

 English translation edited by P. Chalmers 

 Mitchell. Pp. XX + 343. (London : W. Heinemann, 

 1907.) Price 12s. 6d. net. 



MOST people desire to live long, and hence Prof. 

 Metchnikoff 's book is sure to have many 

 readers. He not only discusses the means by which 

 life may be prolonged, but he also examines the ques- 

 tion whether it is desirable to prolong it. About this 

 he has no doubt ; he is a confirmed optimist, and points 

 triumphantly to celebrated men who have begun life 

 as pessimists and have ended it as optimists. The 

 chief of these is Goethe. Several chapters are de- 

 voted to the consideration of Faust, the sorrows of 

 Werther, and Goethe's life. But this part of the book 

 and that which treats of morality will probably appeal 

 to fewer readers than the earlier part, for the sub- 

 jects are so vast and so difficult that it is not easy to 

 deal with them in the short space given to them by 

 the author. 



It is of interest to observe that Prof. Metchnikoff 

 carries his optimism to the point of thinking that 

 living has become easier from a moral point of view 

 owing to the advances of science. For example, as 

 science gets rid of or improves the treatment of 

 plague and diphtheria, there will no longer be any 

 need of the high moral courage of those who went 

 freely among sufferers from these scourges in order that 

 they might alleviate them. Life is already so difficult 

 that this is a point of view we commend to the con- 

 sideration of those who oppose scientific workers, and 

 hinder them by vexatious restrictions. 



" The Prolongation of Life " is a remarkable book 

 in many ways. It and the " Nature of Man," of 

 which it is an extension, treat of a subject about 

 which little has been written. The whole range of 

 literature is ransacked by the author, and the facts 

 and opinions collected are discussed with an origin- 

 ality, a width of view, and knowledge that give the 

 book an especial fascination and constantly arrest the 

 attention. 



Prof. Metchnikoff is of opinion that when old age 

 approaches, tlie phagocytes, which have hitherto been 

 man's friends, become his enemies, and hasten death 

 bv devouring the essential cells of the vital organs 

 of the body, especially those of the nervous system. 



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