17 + 



NA TURE 



[June 20, 1907 



ancient univorsilies. Surely it is not asking too much of 

 s;>me of our most distinguished men of science that they 

 will follow in Huxley's footsteps, and once more bring 

 home to our schools and universities the responsibility Ihoy 

 are incurring by ihfir attitude towards science in the 

 I -Jucation of I he well-io-do classes. 



Eton, June 13. M. D. Hill. 



The Rainbow. 



I.\ '■ Poems by Two Brothers," written by the Tenny- 

 scns, and published in 1827, is a poem called " Phren- 

 ology." The following lines occur: — 



" .Shall we, with Glasgow's learned Watt, maintain 

 That yon bright bow is not produced by rain? 

 Or deem the theory but ill surmised. 

 And call it light (as Brewster) polarised? " 

 Can any of your readers kindly tell me (i) what view 

 was held by James Watt about the rainbow? (2) If 

 Brewster was the fir^t to point out that its light is 

 polarised? Brewster states that he observed the fact in 

 1812. (3) Having regard to the date (1827), w-hat were the 

 most probable sources of information to which the writer 

 cf the poem was indebted? 



I.ord Tennyson kindly informs me that the poem was 

 probably written by Charles Tennyson. 



Ch.xs. T. W'iiitmell. 

 Invermay, Hyde Park, Leeds, June 5. 



The Mass of the o Particle. 



Just too late to prevent the publication of my letter of last 

 week, I perceived that the arguments contained in it are 

 valueless. Rutherford's estimation of the number of o 

 particles is based on the assumption that the charge on 

 each of them is t, and cannot be used to prove that pro- 

 position. The numbers given only show that the heat 

 energy radiated by radium is appro.\imatelv equal to the 

 kinetic energy of the a rays, as has been pointed out by 

 Rutherford. I regret that this foolish mistake should have 

 led me to trespass needlessly upon your valuable space. 

 NoRM.AN R. Campbell. 



Trinity College, Cambridge, June 14. 



Animal Messmates. 



While searching for marine animals on January 14, I 

 came across some large specimens of Ciona inte'stinalis. 

 which I kept for some time in a large bottle, .\fter a 

 while r noticed a small worm emergingfrom the larger or 

 exbalent siphon, which, on examination by a competent 

 authority, proved to be a small example of' the nemcrtine 

 w^rm Drcpanophorus nihrostriatus = Amphiborus specta- 

 hilis, Otrf. Other worms of the same species nfierwards 

 emerged, about ten being observed altogether. The Ciona 

 betrayed no apparent annoyance at the egress cr return of 

 the creatures, though it' withdrew its siphons at the 

 slightest touch of any foreign objects. This observation 

 seems to be a new instance of " animal messmates." or at 

 :'ny rate of the use of an ascidian's test for purposes of 

 shelter by an active creature. 



This has been confirmed on several subsequent occasions 

 by myself and others ; in one instance, a small Ciona, from 

 which not fewer, but possibly more, than fifteen worms 

 issued, the creature was .so transparent that the worms 

 could be ob.served moving about in its interior. 



Frank S. \\'Rir.HT. 



Guernsey, June 10. 



Decomposition of Radium Bromide. 



With reference to Prof. Porter's note in Nature of 

 June 13 (p. 151) on the odour of bromine detected on opcn- 

 irg a sealed tube of radium bromide, it appears that the 

 minimum quantity of bromine that is detectable by smell 

 is between the orders 10-' to io-'° grams per cubic centi- 

 metre of .-lir. This result has been obtained by the pro- 

 gressive dilution of a definite volume of bromine vapour. 

 It may be mentioned that the vapour of bromine is just 

 detectable by its odrur at the temperature of liquid air. 

 .Alfred C. li. Ec.ertox. 



L niversiiy Cillege, London, June 17. 



N*^. 1964, VOL. 76 J 



THE DESTINY OF MAN.' 

 T^HE present volume contains three essays reprinted 

 -'■ from two recent .-iddrcsses and one article by the 

 author. They have been slifji^htly modified and freely 

 illustrated for the present purpose. 'J'he first essay, 

 " Nature's Insurg^^ent .Son," was delivered as the 

 Romanes lecture at Oxford in 1905. It traces the 

 history of man and his rebellion against nature, shows 

 that his inevitable destiny is to transform rebellion 

 into conquest, points to the causes of delay and the 

 special responsibility for their removal which belongs 

 to our universities. 



The second essay, "The Advance of Science," 

 served as the presidential address to the British 

 Association at York in 1906. It gives an account of 

 man's campaign against nature during the last 

 twenty-five years. It is triumphantly successful in the 

 difficult feat of rendering supremelv interesting a brief 

 general account of advance in all the great depart- 

 ments of science. 



The third essav, "The Sleeping Sicl^ness," re- 

 printed from the Quarterly Review, gives an account 

 of this recent terrible scourge of tropical .\frica, and 

 the attempts which have been made to deal with it. 

 This essay is the other side of the picture presented in 

 the second. The latter told of splendid successes in 

 the warfare with nature ; the present essay gives a 

 startling example of those haphazard, unintelligent 

 methods which bring terrible disaster upon man. 



In attempting to give some account of this arrest- 

 ing and important work in the brief limits of the 

 allotted space, I hove thought it best to confine mv 

 attention to the central argument founded on man's 

 history, rebellion and destiny. This argument, de- 

 veloped in the first essay, appeals stronglv to the 

 imagination, and supplies a powerful motive force 

 which has been wanting in the case of earlier appeals 

 for reform. 



" Man is held to be a part of Nature, a product of 

 the definite and orderly evolution which is universal ; 

 a being resulting from and driven bv the one great 

 nexus which we call Nature. He stands alone, face to 

 tace with that relentless mechanism. It is his destiny 

 to understand and to control it." 



This statement of man's origin is rightlv held to 

 contain no implied degradation — rather the reverse. 

 It is only a superficial and ignorant view which sees 

 in evolution the dominion of "chance." "The con- 

 clusion that Man is a part of Nature ... is in fact a 

 specific assertion that he is the predestined outcome 

 of an orderlv — and to a large extent ' perceptible ' — 

 mechanism." It was of importance to urge this con- 

 clusion again, a conclusion set forth, as the author 

 states, by Tyndall in his presidential address to the 

 British .Association at Belfast in 1S74, and again 

 stated and admirablv illustrated by Huxley in 1887.- 

 But the error refuted in 1874 and 1887 was still alive 

 and vi'.jorous in U)oj, and there is reason to fear that 

 even now it is not wholly extinct. 



The emergence of man — perhaps in Lower Miocene 

 times — is shown tn be the grand example of an evolu- 

 tion ;ilso witnessed in other animals. In many of the 

 enrlv Tertiarv Mammalia, as well as in the ancestors 

 of man, it is probable that mechanical form and 

 function had reached a climax. From this point the 

 strutrele was conducted and evolution oroceeded on a 

 hichcr olane, and led to progressive increase in the 

 size and powers of the brain. The author suggestsi 

 the convincing hvnothesis ' that this sudden growth] 



1 "The Klriffrlom nf M»n." Bv K R.iv T.anVewr, F.R.S. Po. xii+191, 

 (London : Archibald rniK'ahle and r„.. I t<. 1007. 1 Pnce «. M. re'. 



2 "The lifs and T.-UTS of Chsiles Parwin." Edited hv Francii 

 r>,r..|n. Vn\. ii.. rbapler v.. Prof. Huxley on the recepiion of ihe| 

 "Or'sjln of Species," pp. lor-201. 



» First Piihlished ^n " c iiiqua-.tenaire de l.l SzcKli de Biologie." Pp. 

 48-51. (Paris 1877.) 



