542 



NATURE 



[August 13, 1908 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



On the Antiquity of Mummification in Egypt — A 

 Correction. 



In a recent article on the history of embalming, which 

 was published in the Cairo Scientific Journal, I stated that 

 a friend had told me there were two left hip-bones and 

 no right in the remains of the so-called mummy of King 

 Mykerinus in the British Museum. 



I have just seen the skeleton, and I hasten to state 

 that my information was not correct, and that there is no 

 reason to suppose that all the bones did not belong to one 

 individual. 



At the same time, I must add that there is no con- 

 clusive evidence to show that the remains found by Colonel 

 Vyse are either mummified or those of Mykerinus. 



This question was raised by me in the course of a dis- 

 cussion on the antiquity of embalming. At the time of 

 writing 1 had seen no genuine mummy earlier than those 

 found at Sakkara in February, 1907, by Mr. J. E. Quibell. 

 They were dated by him as belonging to the period of the 

 tenth dynasty. Since then Prof. Flinders Petrie has 

 directed my attention to a mummy which he found at 

 Medum in 1892. It is assigned by him to the date of 

 Sneferu, the last king of the third dynasty. Prof. Keith, 

 the conservator of the Museum of the Royal College of 

 Surgeons, where this body is now lodged, has allowed me 

 to examine it. The body is certainly a properly embalmed 

 mummy, and if Prof. Petrie's estimation of its age is 

 correct — and it would be presumptuous of me to doubt it — 

 then this specimen shifts back the date when mummifica- 

 tion is known (by positive evidence) to have been practised 

 in Egypt by nearly a thousand years. 



August 7. G. Elliot Smith. 



The Mechanics of the Inner Ear. 



I AM much indebted to Prof. McKendrick for his exceed- 

 ingly fair review of my monograph on the mechanics of 

 the inner ear (Nature, June 4, p. 114). One point, how- 

 ever, seems to require a reply on my part. Prof. 

 McKendrick suggests that I should make " a huge model " 

 of the cochlea. I believe that it is of some general interest 

 to state whv I did not do this long ago. 



One of the most important facts which the engineer has 

 to keep constantly in mind is this, that one can but rarely 

 increase or reduce the size of a machine by making ail 

 parts geometrically similar to the original. In most 

 (especially hydraulic) machines a part of the function 

 depends on volumes, a part on areas, and a part on lines. 

 A linear increase in size of a hundred would involve an 

 increase of all areas by ten thousand, and of all volumes 

 by a million ! 



This principle applies, not only to engineering, but also 

 to biology. Suppose I claimed to have made an artificial 

 amoeba. Prof. McKendrick surely would not deny my 

 claim on the sole ground of my having failed to make 

 one as large as a frog or a fish, if in all other respects 

 it should be a perfect amoeba. Unicellular organisms 

 obviously cannot attain large sizes, because soon their 

 surface functions become insufficient for their volume func- 

 tions, and they have to obtain special organs for the 

 former (e.g. gills). 



In the present case, however, the principle is of a purely 

 mechanical nature. The cochlea is a very tiny hydraulic 

 machine, so tiny that its functional elements are micro- 

 scopical. At the same time, its complexity exceeds that 

 of any machine built by human hand. Anv model would 

 have to be a relativelv huge model indeed. There are 

 three reasons why I did not make any model ; — fi) it is 

 so improbable that in making a model 1 should hit upon 

 proportions which enable the model to function that I 

 would most certainly waste mv time and energv ; (2) if 

 the huge model should (by a kind of miracle) happen to 

 function in accordance with my theory, this would not 



NO. 2024, VOL. 78] 



prove that the cochlea functions likewise ; (3) as soon as 

 it would be known that the model did not function, some 

 would undoubtedly conclude that therefore the cochlea ■ 

 cannot function thus either, although this conclusion is 

 quite unjustifiable. 



Only when, as the result of painstaking experimental, 

 anatomical, and mathematical work, the theory has been 

 greatly perfected will there be any hope of designing and 

 then constructing a huge model which can be expected 

 to function like the inner car. Max Meyer. 



University of Missouri, Columbia, Mo., July 23. 



I QUITE appreciate the force of Prof. Max Meyer's re- 

 marks. The point, how-ever, is that while it would be 

 impossible to make a model of a cochlea that would in 

 all respects work like a cochlea, it would be interesting 

 and instructive to make a large model on the principles 

 so clearly set forth in Prof. Max Meyer's monograph, with 

 the view of ascertaining whether a stroke of a piston 

 (imitating the base of the stapes) would act on the whole 

 length of a membrane (imitating the basilar membrane) 

 or only on a portion of it. , 



A good many years ago I constructed a working model 

 of the cochlea, founded on some suggestions by Prof. 

 Crum Brown. This is described in Schafer's " Text-book 

 of Physiology," vol. ii., p. 1182, and the model is in the 

 physiological laboratory of the University of Glasgow. It 

 illustrated a possible method of analysis, but obvious objec- 

 tions may be urged against its mechanism. Prof. Crum 

 Brown and I have often thought of making a larger and 

 simpler model, and possibly in the leisure we now enjoy 

 we may return to the subject. I w-ould still recommend 

 Prof. Max Meyer to try his hand on a model and put his 

 views to an experimental test. John G. McKendrick. 



Elementary Organic Chemistry ? 



May I be permitted to direct attention to a question 

 asked in a recent examination in organic chemistry for 

 medical students, the syllabus for which states that " the 

 whole subject is to be treated in an elementary manner "? 



The question was : — " On analysis an acid whose melt- 

 ing point was 190° C. gave the following results, 0-2159 

 gram gave 0-3595 CO, and 0-1209 H,0. 



"On titrating with ammonia (i c.c. =0-00334 ^^3), 

 0-4S59 gram of the acid required 37-52 c.c. 



" From these data calculate the molecular formula of 

 the acid." 



Assuming that by the term molecular formula struc- 

 tural formula is meant — else why is the melting point 

 given? — and assuming that the acid does not contain 

 nitrogen, the empirical formula C^HjO^ agrees well with 

 the data given. 



Of the many dibasic acids of this formula, no one melts 

 at igo°, the nearest being dimethylmalonic acid, which 

 melts at 192°. 



But apart from any slight error of this kind, is it to be 

 expected that candidates, in a subject which is to be 

 treated in an elementary manner (or, so far as that goes, in 

 any manner whatever) and who may not consult books of 

 reference during the examination, should be required to 

 know the melting points of all the dibasic acids? 



J. F. Thorpe. 



The University, Manchester, July 29. 



Space and Number. 



In relation to the ideas of Mr. Leonard J. Russell 

 (Nature, July 30, p. 305), it may perhaps be interesting 

 to some of your readers to know that Leibnitz entertained 

 analogous opinions upon the same subject. I quote from 

 Baumann, " Die Lehren von Raum, Zeit und Mathe- 

 matik," Berlin, Reimer, 1869, ii., p. 79: — 



" Die Aufdehnung vorstellen wie ein .Absolutes, 

 entspringt daraus als seiner Quelle, dass wir den Raum 

 vorstellen nach Art einer Substanz, obgleich er ebenso- 

 wenig eine Substanz ist wie die Zeit. Darum haben die 

 Scholastiker einst mit Recht den Raum ohne Dinge 

 imaginar genannt, wie die Zahl ist ohne gezahltes Ding." 

 See my book, " Spazio e temmi," Torino, Bocca, 1908, 

 p. 177- Ottavio Zanotti Bianco. 



Via della Rocca 28, Torino, .August 3. 



