524 



NA TURE 



{April I, 1884 



because it has been already done is so great, and the 

 consequent niateri;il loss to the nation so serious, that the 

 time cannot be far distant when the Governments of this 

 and other countries will have no choice, but yield to the 

 demands made for a moderate annual grant towards de- 

 fraying the expenses incurred in preparing and publishing 

 these indispensable aids to all workers in science. 



OUR BOOK SHELF 

 Berlfs Electrical Directory. Third Edition. (London 



and New York, 1884.) 

 This work consists of three separate directories, sepa- 

 rately paged, but bound up together ; the first, of 228 

 pages, relates to British trades and professions connected 

 with electricity ; the second, of 273 pages, is devoted to 

 similar matters from America ; whilst the third is Conti- 

 nental. Of the last, 71 pages are French and Belgian, 

 12 German, and 3 relate to other countries, chiefly 

 Russia. This arrangement, though convenient probably 

 to the compilers, strikes us as being bad for many pur- 

 poses. The .American and French sections are particu- 

 larly full of information. The British section opens with 

 remarks on the progress made in electrical business 

 during the past year, after which come various tables and 

 formulEE. These are by no means satisfactory. In the 

 formula; for dimensions of units, many of the numbers 

 which should have been printed as powers are given as 

 simple multipliers. Though the table begins with C.G.S. 

 units, and professes to describe those accepted by the 

 British Association and the International Congress of 

 1881, the ohm is given as equal to 10" absolute units and 

 the volt as 10', whereas the figures should respectively 

 be 10'' and 10^. All this is very misleading. So also is 

 thefoUowing statement : — "Calling gravitation the natural 



unit of force, the absolute unit of force will be --—thpartof 



' 9'8i 



it." This statement ushers in the following definition : — 

 " Unit of Mechanical Effect is the unit of force carried up 



through one centimetre, or - -- raised one centimetre." 



° 9-81 



Is it possible that this chapter on formute has been 

 translated literally from the pages of some French wriltr 

 who was in the Iiabit of using a mixed metre-gramme- 

 second system instead of either the centimetre-gramme- 

 second or the metre-kilogramme-second system ? With 

 the exception of the scientific part, the editing appears to 

 have been carefully and soundly done, and the com- 

 mercial information is very extensive. 



LETTERS TO THE EDITOR 



\The Editor does not hold himself responsible for opinions expressed 

 hy his correspondents. Neither can he undertake to return, 

 or to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communications . 



[The Editor urgently requests con espondents to keep their letters 

 as short as possible. The pressure on his spaa is so great 

 that it is impossible otherwise to insure the appearance eirn 

 of comih unications containing interesting and novel facts.'] 



"The Unity of Nature" 



It was, I think, in the course of last year, or of the year 

 preceding, that I ventured to remonstrate against the use some- 

 times made of your columns hy Mr. G. J. Romanes for the pur- 

 pose of inculcating his per.-onal beliefs, and di^beliefs, on lubjects 

 which lie outside the boundaries of physical science. 



The observations made by him in your paper of March 20 

 upon the book I have lately published ("Unity of Nature") 

 show that in that remonstrance I committed an offence which 

 Mr. Romanes has not forgotten or forgiven. Nevertheless I 

 mu^t repeat it ; and this time I have the advantage of his own 

 confession, that "the pages of a scientific journal are not suited 



to an examination " of those parts of my book which he has 

 nevertheless denounced in your pages with unusual violence of 

 language. If your pages are not suited to such an examination, 

 neither can they be suited to comments which nothing but that 

 examination could justify. The tone of these comments is a 

 very clear proof of the necessity of our all keeping within the 

 marches when we meet on neutral ground. Scientific facts and 

 scientific hypotheses constitute that neutral ground. On the 

 other hand, the bearing of these facts and of these hypotheses 

 on c[uestions of philosophy and of religion constitutes a separate 

 region in which, if we meet at all, it mast be outside the pages 

 of a purely scientific journal. In that separate region it has 

 .always been my endeavour to argue without personal passion 

 and without contumely towards opponents. I should be ashamed 

 in any argument to display the animus which has in this case 

 dictated the language of Mr. Romanes on subjects which, by his 

 own confession, he has no right to drag into your pages. He 

 may hold that the highest aim of the human intellect is to prove 

 the mindlessness of nature. My book deah, and was intended 

 to deal, with this philosophy; and I did not expect Mr. Romanes 

 to like it. How much he dislikes it is remarkable. But he 

 will find no passage in it which descends to the level of some 

 of his comments. 



Having dismissed, as irrelevant in your columns, the criticisms 

 of Mr. Romanes on the " Unity of Nature " which have no con- 

 nection with science, I now turn to some of those which have 

 this connection, and are at least perfectly legitimate in their 

 character. 



Mr. Romanes is quite right when he says that I object to the 

 " nnver philosophy" which makes experience the source of 

 in..tinct. In my view this theory is, in the strictest meaning 

 of the word, nonsense, because experience is obviously a 

 " synthesis of intuitions," and not the source of them. It is a 

 plain fact that instinctive movements and instinctive sensations 

 are the conditions precedent — the sole materials — of experience. 

 Experience is nothing but the memory in living creatures of their 

 ov\'u previous action on external things, and of the reaction of 

 external things upon themselves. It is the combined conscious- 

 ness of both w hich builds up \\ hat we call experience. But in 

 every step of this process, whether of action, or of reaction, or 

 of the combined memory of each, not one instinct only, but 

 several instincts are concerned. Experience therefore is the 

 result of instinct, and not the converse. 



With this argument Mr. Romanes does not even attempt to 

 deal. 



He does, however, attempt to deal with my contention that 

 instinct is always strictly correlated w ith organic structure, and 

 that special instincts are always connected with "organs already 

 fitted for and appropriate to the purpose." He says that my 

 own case of the dipper ought to have taught me better ; "for," 

 he add--, " the dipper belongs to a non-aquatic family of birds, 

 and therefore has no organs specially adapted to its aquatic 

 instincts." 



This argument, as an argument, is a non sequitur ; and as a 

 statement of fact is altogether erroneous. It is quite true that 

 the dipper has not webbed feet. But it is not true that webbed 

 feet are at all necessary for aquatic habits of a particular kind ; 

 nor is it true that the dipper is wanting in other peculiarities of 

 structure which are most specially adapted to its peculiar aquatic 

 habits and instincts. There are many birds which swim excel- 

 lently well without webbed feet, as, for example, all the Gal- 

 linules, and some of the Tringidii;. The dipper does not need 

 webbed feet, because it neither swims nor dives in deep water ; 

 and because ou the other hand it positively needs feet free from 

 v\eb for grasping stones under rapid streams, as well as for 

 grasping rock-surfaces in the places of its nidification. On the 

 other hand, the structure of its wings, and above all the struc- 

 ture and texture of its feathers, are all specially modified and 

 adapted to its aquatic habits. 



It is for Mr. Romanes to prove, if he can, that the dipper once 

 had an ancestor which began to dive in water, whilst as yet its 

 wings had not a shape and a texture adapted to the purpose, and 

 whilst its plumage w as still pervious to water, and so was liable 

 to be drenched and sodden. 



Mr. Romanes protests against my suggestion that rudimentary 

 organs may, sometimes at least, be the beginnings of a structure 

 destined for future use, and not the relics of a structure whose 

 use has been in the past. Yet in the same 1 aperhehimselfsuggest'; 

 that the dipper may be on the way to having webbed feet, and 

 only wants them now because it has "not yet had time to de- 



