6o4 



NATURE 



[Oct. 27, 1 88 1 



067? BOOK SHELF 

 Deschnnd's Natural Philosophy. Edited by Prof. J. D. 



Everett. Sixth edition. (Blackie and Son, 1882.) 

 Prof. Everett'.S admirable adaptation of " Deschanel's 

 Natural Philosophy " is so well known as a text-book, 

 that it needs no commendation from us. We heartily wel- 

 come this sixth and greatly improved edition. Amongst 

 the new items we notice that the chapter on thermo- 

 dynamics has been amplified and re-written ; and other 

 parts of the book devoted to heat have also been im- 

 proved, particularly those relating to the apparent mini- 

 mum density of water, and to conduction of heat. We 

 notice also a useful note on the mathematical treatment 

 of the periodical variations of underground temperatures. 

 The section dealing with electricity and magnetism has 

 also been greatly improved. The elements of electric 

 testing by Wheatstone's bridge and resistance coils are 

 now included. The modern dynamo-electric machines 

 and such recent inventions as the electric pen and the 

 induction-balance are described. Rowland's experiments 

 on electric convection-currents, and Plant^'s secondary 

 battery are also mentioned ; though it appears to us that 

 by a slight slip of the pen in the paragraph dealing with 

 Plante's researches his " rheostatic machine,'-' which is in 

 reality a compound condenser of mica plates, is described 

 as a species of commutator (like that of Miiller) for his 

 secondary batteries. There is another slip in the para- 

 graph on the use of the galvanometer for measuring 

 transient currents, for it is stated that the quantity dis- 

 charged through the galvanometer is proportional to the 

 swing of the needle, whereas by the well-known balistic 

 formula of Maxwell, it is proportional to the sine of half 

 the angle of the first swing. These are however minor 

 points. In the section on Light and Sound little has 

 been changed ; the more recent measurements of the 

 velocity of light, and the phonograph, being the most 

 important additions. It is a pity that in the optical 

 formulae the editor does not u?e the same notation as in 

 the a-cepted Cambridge text-books. The problems, 

 which in former editions were lumped together at the end 

 of the book, are in this new edition placed at the ends of 

 the separate volumes, a change which is a great boon to 

 teachers and students who find it most convenient to buy 

 the separate parts. Why the date of 1882 should be put 

 upon a work which appears in October, i88r, is one of 

 the mysteries of publishing which lies beyond the pale of 

 scientific criticism. 



LETTERS TO THE EDITOR 



[ The Editor does not hold h i nisei f responsible for opinions expressed 

 by 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 urgetitly requests correspondents to keep their letters 

 as short as possible. The presstire on his space is so great 

 that it is impossible othenmse to ensure the appearance even 

 of communications containing interesting and novel facts."] 



The Struggle of Parts in the Organism 



As the Duke of Argyll does not appear to have quite under- 

 iitood the meaning which I intended to convey in the paragraph 

 of my review to which he refers, I should lilie to state that 

 meaning a little more explicitly. This I should have done ni the 

 first instance had I not shared the feeling which he expresses, 

 tliat " a purely scientific journal " is not an appropriate place in 

 which to discuss the relations of science to theology, and I shall 

 now hope to show that in my review I did not transgress the 

 border of any such debatable ground. 



My remarks were limited to the " Argument from Design as 

 elaboiated by the natural theologians of the past generation," 

 the material of which was furnished by "the endless number 

 and complex variety of those apparently purposive adaptations 

 of .■•tructures to functions which are everywhere to be met with 

 in organic nature." By this limitation I intended every one 



conversant with the writings of these theologians to understand 

 that I alluded only to the Argument from Design as this was ex- 

 pounded by the school of Paley, Bell, and Chalmers, and which 

 amounted to inferring that particular instances of adaptation were 

 so many separate pieces of evidence pointing to as many 

 "operations of special design." This is the form of teleology 

 which I conceive Mr. Darwin's writings to have completely "sub- 

 verted," for these writings have shown that in natural selection 

 we have a general law whose operation is pre,^Ull]ably competent 

 to produce most of the adaptations previously ascribed to special 

 design. This form of teleology is what I called in my review 

 "scientific teleology," and I did so because it embodied what is, 

 in the full sense of the term, a scientific theory ; certain definite 

 facts or results were observed, and of these results the immediate 

 cause was inferred. Therefore this endeavour to explain the 

 causation of special mechanisms in organic nature properly 

 admits of being discussed in the pages of a scientific periodical ; 

 it is as purely a scientific hypothesis as is that of natural 

 selection. 



But the Duke of Argyll clearly attaches to the term " design " 

 a much wider signification than that which I expressly and inten- 

 tionally assigned to it. For he uses the term in its most unlimited 

 sense, and says : " There are many minds, including some of the 

 most distinguished in science, who not only fail to see any con- 

 tradiction between evolution and de>i;^'n, but who hold that the 

 doctrine of evolution and the facts on which it is founded h.ave 

 supplied richer illustrations than were ever before accessible of 

 the operation of design in nature," &c., &c. 



Here and elsewhere the Duke clearly alludes to the 'whole 

 question of Theism, or of Mind ai the First Cause, and not to 

 the narrower one of this or that particular mechanism in nature 

 as the result of immediate and special design. Now teleology 

 in this larger sense, or the doctrine that behind all the facts open 

 to scientific inquiry (special mechanisms, physical causes, and 

 general laws) there is " Mind and Will " as the ultimate cause of 

 all things — teleology in this sense is a general theory of things 

 which it does not fall within the scope of scientific method to 

 examine. In contradistinction to the cruder teleology of Paley, 

 which, as I have said, may properly be called "scientific," this 

 may be called "metaphysical" — if we use these terms as they 

 are u^ed by Lewes to denote respectively a theory that is veri- 

 fiable (or the reverse) and a theory that is not. The school of Paley 

 thought that the existence of a designing Mind in nature could 

 be proved by a purely inductive method ; Mr. Darwin his since 

 shown that such is not the case ; therefo'e this system of tele- 

 ology is a scientific system, and, like many other theories of the 

 scientific class, it has had to yield to fuller knowledge. But 

 there remains the metaphysical theory of an ultimate design 

 pervading all nature and blending into one harmonious cosmos 

 what the Puke calls the " combination and co-ordination of 

 physical causes " ; and this theory, I quite agree with him, "no 

 possible amount of discovery concerning the physicil causes of 

 natural phenomena can affect," either by way of proof or of 

 disproof. But this has nothing to do with the special question 

 between Darwini-m and "the argument from design as elabor- 

 rated by the natural theologians of the past generation " ; and 

 therefore I shall not discuss the merits of the theory in these 

 columns. George J. Romanes 



"The Micrococcus of Tubercle" 



An article on "Disease Germs," by Dr. W. B. Carpenter, 

 in the current number of the Nineteenth Century, contains the 

 following : — "Another line of inquiry which has obviously the 

 most important bearing upon human welfare is the propagability 

 of the micrococcus of tubercle by the milk of cows affected with 

 tuberculosis, a question in regard to which some very striking 

 facts have been brought before the Medical Congress by a 

 promising young pathologist" — naming myself; and I hope 

 that I am sufficiently grateful to a veteran in science for his 

 complimentary if not altogether accurate reference to my work. 

 What I did say at the recent Medical Congress, and at much 

 grea'er length in a small volume entitled "Bovine Tuber- 

 culosis in Man" (London, 1881) — Dr. Carpenter will find 

 it, I think, among his books — was not anything about "the 

 micrococcus of tubercle," but about a variety of somewhat 

 technical morphological details in respect to which certain 

 cases of tuberculosis in man resembled the tuberculosis or 

 " I earl disease " of the bovine species. I did indeed intro- 

 duce half a page at the end of my essay to show how clear 



