292 



NATURE 



[July 25, 1895 



illustrating the minute structure of oil-drops, and of many 

 of the animal cells described. The evidence of this series 

 of photographs is perhaps even more striking than that 

 of the plates ; and it is well here to draw special atten- 

 tion to them, because the only information given to the 

 English reader as to the means of obtaining them is in a 

 note on p. 341. where it may be easily overlooked. 



The second part of the book contains a short history 

 of the views which have been held concerning the 

 structure of protoplasm, from the time of Remak's early 

 observations on nerve-fibres until the year 1892 ; this 

 is followed by a full exposition of the view that all 

 protoplasm has the foamy structure exhibited by the oil- 

 foams already described, and by a discussion of the 

 difficulties which attend the explanation of all proto- 

 plasmic movement by reference to changes in the surface 

 tension of a foamy substance. 



Such is the arrangement of a work containing the 

 most remarkable attempt to express protoplasmic move- 

 ment in terms of inorganic phenomena which has yet 

 been made. That the attempt is not yet successful in a 

 number of special cases. Prof Biitschli himself is careful 

 to point out ; and the difficulty of explaining in this way 

 the formation of fine thread-like pseudopodia is, as he 

 admits, very great. .-V more serious difiiculty, even in 

 cases of simple lobose motion, is the difficulty of demon- 

 strating those currents in the water outside an amoeba 

 in motion, which should, on the diffusion-theory, exist. 

 These and other points arc clearly stated by Prof. 

 Biitschli, so as to inspire the hope that the final section 

 of his book will lead to the prosecution by himself and 

 his pupils, and by others, of further work on the lines he 

 has here laid down. Without such investigation, any 

 detailed criticism of the difficulties would be simply 

 impertinent. 



Mr. Minchin is to be congratulated on his translation. 

 The original German, while always lucid, is often diflicult 

 to translate, because the author has throughout been in- 

 fluenced on the one hand by a desire to be as brief as 

 possible, and on the other by a spirit of scientific caution ; 

 so that he qualifies statement after statement with 

 epithets which make his sentences easy enough to under- 

 stand, but hard to render into such English as .Mr. 

 Minchin has generally achieved. 



By incorporating the appendix of the original edition in 

 the body of the work, a distinct advantage has been 

 gained ; and a useful feature, wanting in the Cierman 

 edition, is a very excellent index. 



OUR BOOK SHELF. 



.Esthetic Principles. By Henry Rutgers Marshall, M.A. 

 (■.S'ew York and London : Macmillan, 1895.) 



Mk. Maksiiai.i. has done such good work in the field 

 of asthetics that we are glad to welcome this short and 

 simplified exposition of the principles which he regards 

 as fundamental. As we said on reviewing his more 

 tcchni' al treatise, there is good stuff in his work, and it 

 is based on right lines. \Ve have only space to deal very 

 briefly with one or two points on which we are still con- 

 strained to assume a somewhat critical attitude. 



.•Mlhough the view that pleasure is the accompaniment 

 of the using up rif surplus stored energy, and that pain 

 arises when the stimulus calls for an overdraught of 



N". 1343- \"'L. 52] 



energy, may well hold good in certain fields of activity, 

 it does not appear to touch some of the pleasures and 

 pains of special sense. That certain groups of sensory 

 stimuli arc pleasurable, and others painful, seems just as 

 primar)' and inexplicable (and therefore to be at present 

 treated merely descriptively) as that certain light- 

 vibrations give rise to the sensation blue, and others to 

 the sensation red. They are primary datq of "algc- 

 donics," as the colour-sensations are primary data of 

 colour-vision. 



In the helpful classification of " Instinct-feelings," so- 

 called, we think more stress is laid on heredity than the 

 facts at present justify. That there is an innate inherited 

 potentiality of fear, for example, is unquestionable ; and 

 that it is connected with a tendency to tlee from a dis- 

 advantageous object, may be admitted. But the dis- 

 advantageous nature of the object would seem to be a 

 matter of individual experience, aided by the effects of 

 what Mr. Hudson terms tradition through parents or 

 others. It is at least questionable whether the ad- 

 vantageous or disadvantageous nature of the object is 

 "determined by the experience of untold generations of 

 ancestr)-.'' 



The third, and last, point on which we would touch is 

 the delimitation of the ;esthetic field. That w hat is judged 

 to be ;Esthetic appears to be permanently pleasant in 

 revival may be, and in the main is, true enough. But 

 that the relative permanence of the pleasure-field can be 

 regarded as a sufficient icsthetic dilTerentia, we are not 

 prepared to admit. We cannot here discuss the i[uestion; 

 we hold, however, that just as the pleasures and pains 

 of sense on the algedonic accompaniments of sense- 

 experience, so are the distinctively asilutic pleasures and 

 pams the algedonic accompaniments of the perception of 

 relations. .Mr. Marshall's criticisms of the inlellcctualist 

 position (if this view of the purely algedonic accompani- 

 ment of activities, which in their cognitive aspect are 

 intellectual, may be included under this head) is 

 insufiicient to carry conviction. 



We have selected one or two points on which Mr. 

 Marshall's views do not appear to us to be con\ incing ; 

 but it is partly because he is really worth differing from, 

 that we can recommend his work for careful and serious 

 consideration. 



An Analysis of Astronomical Motion. By Henry Pratt, 

 M.D. (London: G. Norman and Son, 1895.) 



Thk present small volume is a contribution to the ever- 

 increasing mass of pseudo-scientific literature, in dealing 

 witli which a scientific reviewer must always lind a 

 difficulty. His first impulse is to ignore such a book 

 altogether, but there are objections to such a course. 

 To preserve strict silence might, in the first place, lead 

 the author, and those who blindly trust his guidance 

 to claim that his work was of real scientific value, since 

 it had been tacitly accepted by the scientific world, or, 

 at least, that his theory could not be confronted by any 

 fatal A priori objections. Kurther, a book of this kind 

 is liable to lead astray the untrained mintls of chance 

 readers, and one's duty to the public requires that some 

 effort should be made to prevent the waste of lime and 

 money over an ignorant and worthless book. 



Dr. Pratt's object in publishing tlie book is to give a 

 simpler expression to the views dev eloped in his earlier 

 work, " Principia Nova Astronomica " (sec N.MlKIs 

 May 17, 1894). He may have found that students needed 

 .additional explanations, or that another advertisement 

 was necessary to assist the sale of the earlier work. If 

 the course were prompted by the first suggestion, one 

 cannot say that the author has been altogether successful, 

 for his theory remains ouite as obscure and unsatisfactory 

 as when first presented. The distinguishing feature of 

 this theory requires our own sun to revolve roimd an 

 " e(|uatorial " sun, which in turn revolves round a " polar" 





