554 



NATURE 



{April 14, 1 88 1 



energy, or rather energy by becoming thought ceases to 

 be energj — is destroyed as energy ; and so this answer 

 would militate against the doctrine in question. If, on 

 the other hand, it is said that thought has no mechanical 

 equivalent, and yet that energy causes thought, the state- 

 ment is still in conflict with the doctrine of conservation, 

 because it supposes that energy in the brain differs from 

 energy everywhere else in producing more than its equi- 

 valent measure of result. How then under any view are 

 we to conceive of thought as an effect of energy? By no 

 stretch of imagination can we attain to the idea of a 

 motor becoming a motive ; and if we could attain to such 

 an idea, it would seem to be at the cost of upsetting the 

 most fundamental doctrine of modern physics. And let 

 it be observed in this connection that Mr. Duncan is not 

 very accurate in the statement of his first "analogy," 

 where he says that " Feeling and Force are alike in bdncj 

 both destitute of space-extension." Force in activity is 

 only known as motion in space, while Feeling in activity 

 cannot be conceived as here or there ; the conception of 

 Force without any actual or potential relation to space is 

 as impossible as the conception of FeeUng in such a 

 relation. 



Mr. Duncan's book, however, is worthy of the attention 

 of psychologists, because although we think his attempt 

 to prove a causal relation between physics and psychics 

 a necessary failure, his work is interesting and suggestive 

 if viewed from the standpoint of Clifford's doctrine of 

 "Mmd-stuff." If we suppose that Force and Feeling 

 are everywhere one, and so that "all the universe is 

 made up of Mind-stufif," we have a logically possible 

 theory which does not labour under any of the logical dis- 

 advantages attending the theory of causality proceeding 

 from matter in motion to mind, or vice versa. Some 

 passages in Mr. Duncan's work seem to show that he has 

 very nearly entered this conception himself; and we 

 therefore feel that he would have written a more valuable 

 treatise if, going a little further, he ,'had discarded the 

 obsolete attempt to explain parallelisms by an impossible 

 theory of eauseility, and undertaken to argue that these 

 parallelisms are really due to a fundamental identity, 

 which, as Lewes puts it, is phenomenally diverse only in 

 relation to our modes of apprehension. 



George J. Romane.s 



LETTERS TO THE EDITOR 



[ TTie 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. A'o 



r J,, ""tice IS taken of anonymous communications. 



L I he Editor urgently requests correspondents to keep their letters as 

 short as possible. Tlie pressure on his space is so great thai it 

 IS impossible otherwise to ensure the appearance even op com- 

 munications containing intereUing and novel facts.} 



Study of the Physical Nature of the Sun 

 Having been engaged for some time past in discussing with 

 that able scientist, the Spanish Astronomer-Royal, Signor 

 Antonio Aguilar, Direc^or-General of both the Astronomica, 

 and Meteorological Ob~enMtories of Madrid, the best method of 

 realising for the requirements of modern science the peculi.ir 

 advantages presented by the Peak of Teneriffe for studying and 

 eliminating the interfering effects of the earth's atmosphere on 

 many classes of astronomical, meteorological, and physical 

 observations— it his just resulted, not exactly in the general 



facilitation which I had hoped for towards the savants of all 

 nations -but in a particular letter to myself of gracious recom- 

 mendation by Spanish royal authority (o the Captain-General of 

 the Canarian Archipelago. 



As however I am totally unable, for reasons well known to our 

 own Government both now and for many years past, to undertake 

 any such research, however useful or pressing— it may be of 

 service to the cause, and to other workers who are more favour- 

 ably situated financially, to make known how hberally the 

 Spanish Government is inclined at the present moment towards 

 any genuine efforts, even of individuals, to improve our know- 

 ledge of the great central luminary by making superior observa- 

 tions with improved instruments at some considerable level above 

 the ordinary clouds and winds of the summer season ; and which 

 superiority of site can only be well obtained on this side of the 

 world by means of that grand Mountain-island which Spain has 

 raled so long and so well,— viz. the Island of Teneriffe. I have 

 therefore now the pleasure of appending a close translation of 

 the official letter, or ra'her Royal Order, from Madrid,— a copy 

 of which Don Antonio Aguilar kindly informs me has already 

 been communicated by the Spanish Government to the Chief 

 Governor of the Canarian Islands. 



" From the Ministry ' de Fomento,' Madrid, to the Director- 

 General of Public Instruction. 



"Illustrious Sir,— In consequence of the Report of the 

 Director-General of the Astronomical and Meteorological Obser- 

 vatories of this capital, the King has deign.^d to order that the 

 Governor of the Province of the Canaries, and all authorities 

 dependent upon him, should give specinl attention to provide 

 whatever assistance he may require to Mr. Piazzi Smyth, Director 

 of the Observatory, Edinburgh, in the expedition which is pro- 

 posed to the Island of Teneriffe, with the object of trying, on the 

 height of the Pe.ik of Teyde, the instruments designed, or im- 

 proved by him for the study of the physical constitution of the 

 Sun, 



" By Royal Order I transmit this to you for your information, 

 and may God preserve you many years. 



"(Signed) 



" On the 22iid March, 1881 " 



A friend well acquainted n ith both England and Spain informs 

 me that we have not in this country any exact analogue to the 

 Ministry "de Fomento." The literary or theoretical meaning of 

 the word is "supporting, encouraging, cherishing"; and the 

 practical result in this case ha^ been, that a poor individual here, 

 unrecommended by the Government, or the greater Learned 

 Societies, or Universities of his own land, but having an excelsior 

 natural object to labour at, has received this very honourable 

 testimony and encouraging recommendation. All honour then 

 to the Government of Spain therefor ; and may they meet at 

 last with a more worthy subject for their gracious " Fomento," 

 'h3u Your obedient servant, 



Edinburgh, April 9 Piazzi Smyth 



Winter Gnats (Trichocera) 



The winter gnat {Trichocera hiemalis, D. G.) is one of the 

 subjects of phenological observations undertaken by the Meteo- 

 rological Society. Its appearance directly after long-continued 

 frost, often whilst the thaw is in progress, has frequently led 

 entomologists to inquire whether the insects then seen have been 

 hybernating during the cold weather, or have newly emerged 

 from the pupa. No evidence has been adduced in support of 

 either alternative. Some facts concerning the habits of the fly, 

 noted as opportunity occurred during the last two winters, bear 

 upon the matter in question, and may therefore be of interest to 

 both the above classes of your readers. The name Trichocera 

 hcmalis is used here in its meteorological sense, for nobody 

 would pretend to distinguish this aliundant species at a distance 

 from the common T. rcselationh. 



