December 19, 1895] 



NATURE 



149 



iically the sole factor in determining the intensity of the 

 reflected light." 



In chapter v. the distinguishing characteristics which 

 separate surface-colours from other classes of colours are 

 noted. The following kinds of colours are treated : (i) 

 body-colours ; (2) the colours of turbid media ; (3) the 

 prismatic dispersion colours ; (4) the spectral colours of 

 the diffraction grating ; and (5) the colours of thin 

 plates. With reference to the latter, the author calls 

 attention to the fact that if one changes the polarisation 

 of the incident light used in producing the colours of thin 

 plates, the result is simply a change in the intensity of 

 the colours, no change in their tint being thereby caused ; 

 Avhereas with surface -colours proper, under the same 

 ■circumstances, both intensity and tint axe. thereby changed. 

 The body of the work concludes with a sixth chapter, 

 dealing with the occurrence of surface-colours in the 

 animal and mineral kingdoms. E. H. B. 



OUR BOOK SHELF. 



Studies from the Biological Laboratories of the Owens 

 College. Vols. i. (pp.' 328), ii. (pp. 268), iii. (pp. 286), 

 1886, 1890, and 1895. (Manchester: Cornish.) 



There is growing up among us a habit of collecting and 

 publishing reprints of memoirs as " Studies " from this 

 laboratory or from that ; and a very excellent habit it ap- 

 pears to us to be. We have known for some years the 

 *■' Studies from the Morphological Laboratory " of Cam- 

 bridge ; we have seen " Reports " from the Physiological 

 Laboratory of University College, London ; " Transac- 

 tions "from Dundee, edited by Prof. D'Arcy Thompson, 

 and quite recently we referred to the youngest of such 

 publications, viz. the " Linacre Reports " of the zoological 

 work at Oxford, edited by Prof Ray Lankester. 



All such collections serve the useful purpose of indi- 

 cating the character and amount of work carried out at 

 the various important teaching institutions of the king- 

 dom, and of emphasising the fact that the best teaching 

 Avork is performed by those engaged in research. It 

 may be objected that the memoirs contained in such 

 " Studies " can be found elsewhere. This is, in general, 

 true ; but, nevertheless, such collections help to associate 

 more readily in our minds the workers with their masters 

 and the institutions to which they are attached ; and 

 oftentimes it brings together, in a compact form, a series 

 of contributions undertaken with some special object, by 

 different workers it may be, or by one man. 



The first volume of these " Studies " from Manchester 

 was published in 1886, the second in 1890, the third 

 •during the present year ; the last is under the editorship 

 •of Dr. Sydney Hickson, the two former by the late 

 Professor. These volumes contain several valuable 

 memoirs, some of which are already classical, such as 

 Marshall's "Segmental Value of the Cranial Nerves," 

 Beard's account of the Branchial Sense-organs, and 

 Melland's contribution to the Histology of Striated 

 Muscle ; and to these will have to be added, no doubt, 

 the researches of Marshall and Bles on the Development 

 of the Vascular System, and of the Kidneys in the Frog, 

 Robinson's observations on the Development of the 

 Optic Nerve, Paterson's account of the Origin of the 

 Nerve-plexus of the Limbs, and other embryological 

 papers undertaken at the suggestion of the late Pro- 

 fessor. 



In addition to these developmental memoirs, those by 

 Fowler on the anatomy of Corals, and by Garstang and 

 by Gamble on the Fauna of the British Coasts, have a 



NO. 1364, VOL. 53] 



permanent value. In the last volume, Milnes Marshall's 

 interesting "Address" at the British Association, dealing 

 with " Recapitulation in Ontogeny," is reprinted. 



The absence of botanical research in the later volumes 

 is the more noticeable, as Prof Marshall Ward con- 

 tributed to the first volume. We hope that botanical 

 research is not dead in Manchester. 



Palaeontology is represented by Dr. Hurst's account of 

 Archaoptcryx. 



The quality and extent of ten years' work brought 

 together in these three volumes, bear witness to the energy 

 and influence of the late Beyer Professor ; and we may 

 echo Prof. Hickson's prefatory remark, that "his in- 

 fluence will long be felt in the writings of his pupils 

 and successors." 



Studies in Economics. By William Smart, M.A., LL.D. 



Pp. 341. (London : Macmillan and Co., 1895.) 

 Dr. Smart is favourably known in the economic world 

 by his admirable translations of the writings of the 

 Austrian school ; and in these " Studies " the character- 

 istic doctrines of that school furnish no small part of the 

 theoretic apparatus. The exclusive emphasis laid on 

 that side of the theory of value, the elaboration of 

 which is connected in this country chiefly with the name 

 of Jevons — the side of demand, that is, with its controlling 

 factor of marginal utility — is faithfully reproduced by Dr. 

 Smart ; and, like the teachers, whose disciple he frankly 

 acknowledges himself to be, he is disposed to treat as 

 " secondary " and " derivative " that influence of cost of 

 production as governing supply, and, through supply, 

 determining value, to which the older English economists, 

 such as Ricardo and Mill, assigned predominant stress. 

 He describes the Austrian theory as the " current " and 

 "dominant" theory ; and, while he sometimes accords a 

 hesitating recognition to conceptions which seem to conflict 

 with this exclusive emphasis, his attitude even here appears 

 to be in reality one of doubtful acceptance rather than 

 hearty concurrence. To the writer of this review the later, 

 like the older emphasis, seems mistaken ; and the com- 

 prehensive attitude of Prof Marshall, who treats the two 

 sides of supply and demand as mutually determining, 

 appears to be more closely in accord with the facts ; and 

 in this impression he is strengthened by the difficulties 

 encountered by Dr. Smart in some of these " Studies " 

 from an unwillingness to allow to cost of production a 

 coordinate influence with that of marginal utility in 

 determining value. On Prof Marshall's hypothesis the 

 facts seem to fall naturally into their place, but by the 

 Austrians and by Dr. Smart they appear to be forced 

 artificially into a strained position. To this theoretic 

 equipment Dr. Smart has added the valuable qualification 

 of a first-hand acquaintance with the facts of business 

 life ; and the advantage of this intimate knowledge is 

 evident in many parts of his book. It consists of three 

 main sections, one devoted to studies in wages, the 

 second to studies in currency, and the third to studies 

 in consumption. Of these the first seems to us the 

 most valuable ; and the reason consists in the fact that 

 Dr. Smart's business experience brings a strong admixture 

 of practical sagacity to bear on such matters of concrete 

 interest as a " living wage," the " sliding scale," and 

 " women's wages." He owns in his preface to a prone- 

 ness, not unnatural in a business man, to " lose himself 

 in the fallacy of the particular instance " ; and we are not 

 sure that he has in the course of these " Studies " always 

 avoided this fallacy. But he never fails to be interesting 

 and suggestive, and he is, with rare exceptions, uniformly 

 lucid ; and these are qualities as admirable as they 

 are rare in combination. The economic student and — 

 in a more especial degree — the practical man, will find 

 material for profitable reflection in the careful perusal of 

 these interesting " Studies." 



