May 20, 1875 1 



NATURE 



M 



hJD'^ + 98- ; the reflected sounds which reach the observer will 

 travel double those distances. 



D {D- + S=) (D- + 45-) &c., being integral quantities, and 5 

 positive, the series will be an increasing one ; hence the first 

 impulse which is heard is that produced by d, and the last one 

 that by r;'„. 



Twice the difference between any term and that which imme- 

 diately precedes it will be the length of the sound-wave corre- 

 sponding to that term, and the velocity of sound per second, 

 divided by the wave-lengths, gives the relative pitches of the 

 different impulses. 



The wav e-length s correspondi ng to dd ^^ d.^ &c . are — 

 2(V/J-'-i-8-^ - D);2 { y/J ^ f 45-^ - s.'n-'^ + 5-) ; 



2( sjD'^ + 952 - »jn-' + 45-) &c, (i.) 



And calling V the velocity of sound per second, we get the rela- 

 tive pitches — 



^ , — .=£ =- &c 



2( VZ)« + 8'-2 - £>)' 2{ s'U^ + 452 - VZ)2 + 52) 



Now, if the observer removes close up to the fence, the distance 

 D becomes an indefinitely small quantity, or zero, and the 

 series (i) for the^ wave-lengths becomes 2 ^''8- ; 2(2 v'S- - \/5') ; 

 2(3 V'S'"- 2x/r); 2(4 v' 5^ - 3\/5'). &c., or 28, 28, 28, &c. ; 

 that is, the wave-lengths are all equal, and a musical sound is 

 heard. In practice, an ordinary fence does not yield a suffi- 

 ciently loud note to be easily heard in this case, but one made 

 with posts having intervening spaces of about five inches gives 

 a good result when one stands four or five feet from it, the note 

 comes out almost perfect. By taking different values for D we 

 have from series (i) a corresponding change of wave-lengths, so 

 that if a row of persons are placed from o to d, each will hear a 

 sound which is different in pitch from that heard by all the 

 others. 



It is perhaps needful to state that the sound which has been 

 described is completely masked if there are houses or a wall a 

 few feet behind it, or if the place of observation is a road fenced 

 with palisades ©n both sides, two sounds are produced which 

 interfere and confuse each other, 



Glasgow Andrew French 



The Degeneracy of Man 



The numbers of Nature for June and July last, which have 

 lately reached me (vol. x. pp. 146, 164, 204 and 205), contain a 

 correspondence on the subject of the degeneracy of man, in con- 

 nection with which I wish to contribute a few remarks. 



I have nothing to say on the original point introduced by Mr. 

 E. B. Tylor. But, during my residence in the islands of the 

 Pacific, I have given some attention to the general question of 

 degradation or progression, as exhibited in the Polynesians. 

 The result is, that I believe there are numerous indications of 

 the degeneracy of these people from a higher social and intel- 

 lectual level than that which they at present occupy. I could 

 not give in detail, in this letter, the entire evidence on which 

 this opinion is based ; I will therefore briefly mention two or 

 three indications only of this degeneracy which I have noticed. 



The language of the Polynesians furnishes one of these. 

 ^Vhile there is much in it which shows a low moral tone, there 

 are, on the other hand, many refinements (a large proportion of 

 •which are known to most of the present generation) which I do 

 not believe could have been invented, or gradually developed, 

 by the r.ice in its present intellectual condition. Their old tra- 



ditional stories, and their ancient poetry also, are so different 

 from anything the present Polynesians are capable of producing, 

 that I often think (your classical readers will please pardon the 

 comparison) the relative difference, between the past and present, 

 is a? great as that between the intellect of the Greeks, in the 

 period of the highest Attic culture, and those of the present 

 century. I have often asked men of more than average intelli- 

 gence, why their modern compositions are so inferior to many of 

 the old ones. They invariably reply that the men of old were 

 greater and wiser than those of the later generations. 



The industrial and ornamental works of the Polynesians are 

 all, I believe, of ancient origin. Their houses, their canoes (with 

 one exception), their fine mats, the way in which they make their 

 bark cloth, and even the patterns wliich they print on it, are all 

 according to the traditional forms handed down from generation 

 to generation. There is no originality. Invention is unthought 

 of. Even now, when the influence of external civilisation is 

 brought to bear with considerable force upon them, they adopt 

 a new idea ver)', very slowly. If they had never been in a higher 

 and more active intellectual condition, I cannot conceive how 

 they could possibly have obtained the many comparatively 

 excellent customs, the — in many respects — elaborate language, 

 and the advanced social customs which were in their possession 

 when first they became known to the civil. sed world. 



I am well aware that absolute proof of the degeneracy of the 

 Polynesians will not, by any means, render necessary the con- 

 elusion that degeneracy has been universal with the human race. 

 Advocates of the progressive theory do not deny that some 

 instances of degradation are to be found. In his "Primitive 

 Culture" (vol. i. p. 34) Mr. Tylor says : " Of course the pro- 

 gression-theory recognises degradation, and the degradation- 

 theory recognises progression, as powerful influences in the course 

 of culture." Hence I present the indications of degeneracy 

 above-mentioned as, at most, only a minute portion of the cumu- 

 lative evidence which must be adduced indisputably to prove the 

 degradation-theory of general application to the human race. 



Apropos of this question I may add, that I often think much 

 of the difference between (at least the more moderate) progres- 

 sionists and degradationists is owing to the want of a clear 

 definition of the term civilisalioii as used on either side. One 

 appears to me to think chiefly of a material civilisation, while 

 the other thinks mainly of a moral civilisation. I do not believe 

 in the evolution of man from a lower form of life. But, notwith- 

 standing this, I doubt whether the first man was civilised in the 

 ordinary sense in which that word is now used. So far as a 

 material civilisation goes, I take him to have belonged to 

 the earliest stone age. But at the same time I feel the 

 strongest conviction that he was, in point of moral civilisation, 

 immeasurably in advance of a savage. It has often been said by 

 advocates of the degradation-theory that no well-authenticated 

 instance has ever been given of a savage who has, apart from 

 external help, improved his condition. I believe this assertion to 

 be true, notwithstanding Sir John Lubbock's " Cases in which 

 some improvement does appear to have taken place," given in 

 the appendix to his " Origin of Civilisation " (pp. 376-380), I 

 do not deny the force of tfie reply to the above assertion, given 

 by advocates of the progression-theory ; viz., that it is almost 

 impossible to prai'e that a savage race has, unaided by external 

 influence, bettered its condition. But from personal observation 

 of savage and semi-savage life, I feel almost certain that a real 

 savage is utterly incapable of, in any way, raising himself. He 

 lacks the sensibility which must serve as a fulcrum for the lever 

 which is to lift him. Upon this ground alone, if I had no other 

 reason for it, I should doubt whether man had, unaided, deve- 

 loped himself from a state of unmitigated savagery. 



Upolu, Samoa S. J. Whitmee 



The Law of Muscular Action 



In NATtJRE vol. xi. p. 426, my esteemed friend Prof. Kin- 

 richs does me the honour to comment on my paper published in 

 Nature, vol. xi. pp. 256 and 276. 



He claims to have found that in lifting a weight 10 until ex- 

 haustion sets in, the number of lifts n is represented by the 

 equation — 



^ \ 



"-i- („ 



or log. « = log. A — w log. Bi ) 



where A and B are constants. 



That the relation between n andtc (the strength of the muscle 



