322 



NATURE 



[June 26, 1919 



These two text-books on forest law by Mr. 

 J. P. Kinney form an important contribution to 

 the rapidly growing- mass of American forestry 

 lierature, and impress one with the painstaking 

 way in which authorities and cases have been cited. 



INORGANIC AND PHYSICAL 

 CHEMISTRY. 

 (i) Recent Discoveries in Inorganic Chemistry. 

 By J. Hart-Smith. Pp. x + 91. (Cambridge: 

 At the University Press, 1919.) Price 45. 6d. 

 net. 



(2) Recent Advances in Physical and Inorganic 

 Chemistry. By Dr. Alfred W. Stewart. With 

 an introduction by Sir William Ramsay. Third 

 edition. Pp. xv + 284. (London : Longmans, 

 Green, and Co., 1919.) Price 125, 6d. net. 



(3) • Osmotic Pressure. By Prof. Alexander 

 Findlay. Second edition. (Monographs on 

 Inorganic and Physical Chemistry.) Pp. xi + 

 116. (London: Longmans, Green, and Co., 

 1919.) Price 65. net. 



(i) " "DECENT Discoveries in Inorganic 

 -tV Chemistry " is a summary of facts 

 culled from the literature of inorganic chemistry 

 during the last fifteen years or so. "The book 

 is in no sense intended to be a text-book, but is 

 rather to be regarded as a supplement to existing 

 text-books." Regarded from this point of view, 

 the little volume fulfils its object. It will serve, 

 at any rate, to indicate many of the more im- 

 portant subjects of recent inorganic research, 

 although the account given of each is in general 

 so brief that the original work and the collateral 

 literature will have to be consulted. As the book 

 stands, the title is rather too comprehensive. 



(2) This book, which has now reached its third 

 edition, consists of twenty chapters, eight of 

 which are devoted to inorganic problems, four to 

 radio-activity, and six to physical chemistry. It 

 is written in a very clear and lucid style, and is 

 eminently readable. Arbitrariness in the choice 

 of the material discussed is almost inevitable in 

 a book of this size. Thus whilst we find an 

 excellent account of such subjects as radio-activity, 

 X-rays and crystal structure, atomic numbers, 

 and analysis by means of positive rays, we do not 

 find any consideration of the modern advances 

 made in chemical thermo-dynamics (such as the 

 Nernst heat theorem), nor an account of the 

 quantum theory, photo-chemistry, colloids, the 

 work of Perrin and of Millikan on the determina- 

 tion of the Avogadro constant, the work of Lang- 

 muir on surface action, and the modern views of 

 allotropy. Perhaps the least satisfactory chapter 

 is that which deals with the structure of the atom. 

 The subject is admittedly difficult to treat, but the 

 author is scarcely justified in devoting a single 

 paragraph to the Rutherford-Bohr atom, whilst 

 giving a page to the purely geometrical atom 

 model of G. N. Lewis, and five pages to his own 

 atom, from which no quantitative results have as 

 yet been obtained. Further, the gibe at the school 

 of Ostwald in chap, xx., and the reference to 

 NO. 2591, VOL. 103] 



the "thirty years of relative stagnation" from 

 which physical chemistry is supposed to have 

 suffered, are singularly inappropriate. As a 

 matter of fact, the portions of the book which 

 deal with inorganic chemistry and radio-activity 

 are very much more satisfactory than the treat- 

 ment of physical chemistry. 



(3) Prof. Findlay 's monograph on osmotic 

 pressure is already so well known that it is only 

 necessary to direct attention to the fact that a 

 second and enlarged edition has now appeared. 

 After dealing with the problems of the exp>eri- . 

 mental measurements of osmotic pressure for both f 

 dilute and concentrated solutions. Prof. Findlay 

 goes on to discuss in some detail the significance 

 of the results obtained. This devcxops into a most 

 illuminating account of the theory of solutions, 

 involving a consideration of the allied properties, 

 vapour pressure, lowering of freezing-point, and 

 rise of boiling-point. Stress is rightly laid upon 

 the necessity for distinguishing between the 

 thermo-dynamic significance of osmotic pressure 

 and the various attempts which have been made 

 to picture the mechanism on a molecular basis. 

 An equally clear distinction is drawn between 

 osmotic pressure itself, the phenomenon of 

 osmosis, and the mechanism of permeability of 

 the membrane. The monograph is indispensable 

 to every physical chemist. 



W. C. McC. Lewis. 



i 



THE PRIMITIVE NERVOUS SYSTEM. 

 The Elementary Nervous System. By Prof. 



G. H. Parker. (Monographs on Experimental 



Biology.) Pp. 229. (Philadelphia and London : 



J. B. Lippincott Co., 1919.) Price 2.50 dollars 



net. 

 "D ECENT research on the functions of the 

 ^^ nervous system of man and other mammals, 

 such as Head's clinical observations and Sher- 

 rington's experimental work, has revealed the 

 fact, which had not been adequately recognised 

 before, that many of the most archaic dispositions 

 of the primitive nervous system have survived in 

 the highest vertebrates, where, as a rule, they 

 are disguised and hidden from view by the more 

 obtrusive features that give the vertebrate nervous 

 system its distinctive character. 



The need for a fuller and more accurate know- 

 ledge of the nature and origin of the earliest 

 nervous mechanisms has thus become more 

 insistent and essential to everyone who is attempt- 

 ing to> understand fthe working of any of the 

 more complex types of nervous system. 



For some years, and especially during the last 

 ten, Prof. Parker, of Harvard, has been 

 investigating the simpler types of neuro-muscular 

 apparatus, and has published (mostly in journals 

 that are not easily accessible) a series of memoirs 

 dealing not merely with the structure, but also 

 with the functions, of this system, making use of 

 the exact methods of modern quantitative 

 measurement to estimate and express the results 

 of his experiments. 



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