530 



NATURE 



[April 4, 1S95 



which forms a large part of the chapter dealing with 

 "the mechanism of life." 



The author'claims for his work, that it is essentially an 

 exposition of " cellular physiology." I am myself inclined 

 to think that he exaggerates the value of this point 

 ol view. The idea of the cell, important as it has been, 

 and still is, when we deal with the cell as a morphological 

 unit, seems to me of much less importance when we deal 

 with it as a physiological unit. But I pass this over, in 

 order to join issue with the author on two other matters. 

 He speaks "of the impotence of the physiology of to- 

 day, when brought to face the simplest processes of life," 

 and writes as if all the knowledge which, especially during 

 the last thirty years, has been gained by the application 

 of exact physical and chemical methods to the study of 

 the phenomena of life, simply led to the end of a blind 

 alley. He urges that, while we are rapidly approaching 

 perfection in these things, we yet are impotent in face of 

 the deeper problems. He even goes very near repeating 

 the taunt of the Philistine, "\Vith all your boasted pro- 

 gress, you are still unable to tell us -what life is" with, 

 however, the difference that he uses the taunt in order 

 to incite physiologists to adopt other methods of inquiry. 

 I venture to think; that in this the author is quite 

 wrong. Not only has the progress of physiology, due to 

 the use of exact methods, been remarkable during the 

 last half-century- or so, but also by those methods we have 

 been drawn measurably nearer the inner and hidden 

 mysteries. To take one instance among many, the 

 application of exact physical methods to the study 

 of muscles, so far from having brought us to a point 

 beyond which we cannot go, seems just now to 

 be opening up the way to fruitful conceptions of the 

 intimate nature of muscular contraction — conceptions 

 which would have been impossible in the absence of the 

 knowledge gained by the graphic method. Two armies, 

 from two different sides— one physical, the other chem- 

 ical— are attacking that difficult — to some it seems im- 

 pregnable— fortress. They have alreadyl gained many 

 of the outwoiks ; they are pressing on, drawing nearer to 

 each other ; and when they touch hards, they will do 

 that which will put to shame all scofis at their impotence. 

 Then again, the author finds fault with the prepond- 

 erant attention given by physiologists to the study of the' 

 higher vertebrate animals ; he blames them for their 

 comparative neglect of the lower and, especially, of the 

 lowest invertebrate forms. It is not for mc, who in my 

 rash youth had wild dreams of building up a new physio- 

 logy by beginning with the study of iheanuLba, and work- 

 ing upwards, to say one word against the experimental 

 investigation of the lower forms of life. Hut experience 

 and reflection have shown me that, after all, the physio- 

 logical world is wise in spending its strength on the 

 study of the higher animals. And for the simple 

 reason that in these, everything being so much more 

 highly differentiated, the clues of the tangles come, so to 

 speak, much more often to the surface, and may be 

 picked up much more readily. Taking again, as an 

 instance, the molecular processes which give rise to the 

 movements of animals, and which appear under such 

 forms as that of amn-boid movement, and that of the 

 contraction of a striated muscle, 1 venture to think that 

 the very apparent simplicity of the former is an obstacle 



NO. 1327, VOL. 51] 



to our getting a real grasp of its inner nature, and that 

 by our studies of the complex muscle, we are drawing 

 nearer to such a grasp than we could ever have done b\ 

 observations confined to the phenomena of the amcx^ba 

 itself. And so in many other instances. The study of 

 the lower forms of life is, in reality, more dift'icult than 

 that of the higher forms : and the latter naturally comes 

 first. At the same time the author will have the sym- 

 pathy of :\11, if his contention be limited to the assertion 

 '• that the full fruition of physiological truth can only be 

 reached by the careful study of all forms of life, whether 

 high or low ; this, indeed, his own special investigations 

 have already shown, and in this sense the contribution 

 to a "general physiology," which his present volume 

 offers, is gladly welcomed by us all. M. Foster. 



NERNSrS THEORETICAL CHEMISTRY. 



Theoretical Chemistry, from the Standpoint of Avo- 

 iiadro's Rule, ami Thermodynamics. By Prof. Walter 

 Nernst, Ph.D. of the University of Gottingen. Trans 

 lated by Prof. Charles Skeele Palmer, Ph.D. of the 

 University of Colorado. Pp. XXV.-697. (London : 

 Macmillan and Co. 1895.) 



NO one can compare the knowledge we possess 

 to-day of the conditions and general laws of 

 chemical change with the state of our knowledge ten 

 years ago, without being much impressed by the enormous 

 advances made in the last decade. .Accurate and 

 generalised knowledge of physical chemistry did not 

 exist ten or twelve years ago. What is practically a new- 

 science has arisen, based on the work of such men as 

 Guldberg and Waage, van't Hon', Ostwald, Arrhenius, 

 Nernst, Raoult, (iibbs, and Thomsen, who built upor» 

 the foundations laid by Dalton, Avogadro. Berthollet, 

 Faraday, Helmholtz, Thomson, and Clausius. The 

 special mark of the new science is that it has been pro- 

 duced, to use the words of Nernst, "by the co-operatiot> 

 of two sciences which hitherto have been, on the whole, 

 quite independent of each other." One hardly knows 

 whether to speak of physical chemistry or chcmicil 

 physics. 



The text-book of this new science is Ostwald's " Lehi- 

 buch der Allgemeinen Chemie." Notwithstanding the 

 thoroughly satisfactory character of that work, there ' 

 was room for another book which should treat the sub- 

 ject in less full detail, and which should pay especial 1 

 attention to the data and the conceptions that have been \ 

 systematised and applied in a general way. Prof. Nernst 

 has written exactly the book that was wanted ; and this 

 book now appears in a form which brings it within the 

 reach of all English-speaking students. 



The 7 hcorelical Chemistry oi Prof. Nernst deals with 

 (l) the universal properties of matter, (2) the atom and 

 the molecule, (3) the transformations of matter, and 



(4) the transformations of energy. The first section 

 treats of (1) the gaseous, (2) the liquid, (3) the solid, 

 state of aggregation, (4) the physical mixture, and 



(5) dilut; solutions. The second section is devoted to 

 (l) the atomic theory, (21 the kinetic theory of the mole- 

 cule, (3) the determination of molecular weight. 141 the 

 constitution of the molecule, (5) physical properties 

 and molecular structure, (6) the dissociation of gases. 



