October 20, 1923] 



NA TURE 



579 



matical symbols ; for the student is only too apt to 

 take the easier course, and consider the formula and not 

 the fact as the physical reality." In effect this makes 

 the section on elliptic orbits sad reading ; we are also 

 given Sommerfeld's admittedly unsatisfactory attempt 

 to give a theoretical basis for Ritz's term-form. It is 

 much to be desired that we might have had instead 

 Bohr's elegant proof of the Rydberg form for central 

 orbits (now superseded, as mentioned above), which is 

 both physically and mathematically unexceptionable. 

 It is possible that this was not available to the author, 

 though it has been current for some time. 



It is only just and right, however, that this review 

 should close as it began on a note of praise, for the merits 

 of the book are many and its defects few. No one can 

 have anything but praise for the system and selection of 

 references which leave nothing to be desired, and for the 

 exquisite photographs by Blackett, Aston, Paschen, 

 Siegbahn, and de Broglie reproduced in the four plates. 

 The book should go through many editions — the more 

 the better. R. H. Fowler. 



The Physical Aspect of Physiology. 



(i) Inter Jacial Forces and Phenomena in Physiology : 

 Being the Herter Lectures in New York in March, 

 1922. By Sir William M. Bayliss. Pp. ix-f-196. 

 (London : Methuen and Co., Ltd., 1923.) 75. 6d. 

 net. 



(2) The Vaso-Motor System. By Sir William M. 

 Bayliss. (Monographs on Physiology.) Pp. v + 163. 

 (London : Longmans, Green and Co., 1923.) 7^. 6d. 

 net. 



(3) The Electrical Action of the Human Heart. By 

 Dr. Augustus D. Waller. Edited by A. M. Waller. 

 Pp. ix + 103. (London: University of London 

 Press, Ltd., 1922.) 75. 6J. net. 



II 



OWEVER distinguished a man of science may 

 be, we still expect the books he writes to 

 increase his reputation. These two books by Sir 

 William Bayliss will scarcely do this. It is not that 

 they are bad books, but that they are not good enough 

 for so distinguished an author. 



(i) The volume on " Interfacial Forces and Pheno- 

 mena in Physiology " is lucid and readable, and will 

 certainly stimulate to further thought many who are 

 interested in the problems lying on the borderland 

 between the physical and the biological sciences ; 

 but here its virtues end. In the first chapter we are 

 introduced to the electron theory of the atom and the 

 latest work on crystal structure ; but the promise 

 of this chapter is not maintained. The treatment 

 of the subject is almost exactly the same as that in 



NO. 2816, VOL. I 12] 



the first edition of the author's " Principles of General 

 Physiology." Though the advances of the intervening 

 seven years are mentioned their bearing is not always 

 recognised. For example, Sir William BayHss per- 

 sists in calling protein solutions " emulsoid," while 

 confessing that emulsions never behave like protein 

 solutions, and he makes no use of the insight into the 

 constitution of colloidal solutions that the work of 

 McBain gives us. It is probably the hypnotic effect 

 of the word " emulsoid " that makes the author assume 

 that a protein solution must inevitably behave as a 

 heterogeneous system. 



The classical theories of surface tension and adsorp- 

 tion are all based on statistical mechanics, and it is 

 just when we come to the mechanism of the living 

 cell that statistical theory fails us. These theories 

 have been available to physiologists for many years 

 and have been of scarcely any use because no precise 

 deductions can be made from them in connexion 

 with physiological problems. The new treatment of 

 surface phenomena that we owe to Langmuir and to 

 Adam holds immense possibilities for the physiologist, 

 yet Sir William Bayliss dismisses Langmuir almost 

 summarily. There are cases where statistical theory 

 is of use to physiologists, notably in the treatment of 

 processes that go on in a relatively simple medium, 

 such as blood. The particular theory that has proved 

 of most use here is the Law of Mass Action, but this 

 law we are told we ought not to use. Sir WiUiam 

 Bayliss adopts the attitude of one who reproves a 

 friend for removing a nut with hammer and cold chisel, 

 while he admits that the only spanner available does 

 not fit. 



(2) The book on " The Vaso-Motor System " is 

 more purely technical. It contains a useful summary 

 of the work done on the control of the blood flow 

 through arteries and capillaries. Much of the evi- 

 dence at present available is confused and conflicting. 

 As one of the most successful investigators in 

 this branch of physiology, we might reasonably have 

 expected Sir William Bayliss to sum up the evidence 

 judicially, and to give us the benefit of his conclusions 

 on doubtful points. This he does not do. He merely 

 states all the results obtained by all the workers, and 

 leaves the reader to pick his way among them as best 

 he can. 



(3) The late Prof. Waller's book on " The Electrical 

 Action of the Human Heart " consists of a series of 

 four lectures delivered by the author in 1913. The 

 first two lectures contained a resume of certain facts 

 and theories based on the author's work with the 

 capillary electrometer, and a comparison of these 

 early results with those obtained by means of the 

 string galvanometer of Einthoven. The remaining 



