REVIEWS 687 



page 47, is not sufficiently explained. It should be omitted altogether or else fully 

 described in the text. 



The book closes with the ominous sentence, " No process of any kind for the 

 fixation of atmospheric nitrogen has yet been established in Britain." Happily 

 we may add, the signs are not wanting that at last this standing reproach to 

 British industry is to be in some measure abated. 



C. S. G. 



Quantitative Laws in Biological Chemistry. By Svante Arrhenius, Ph.D., 

 M.D., LL.D., F.R.S. [Pp. xi + 164.] (London: G. Bell & Sons, 1915. 

 Price 6.y. net.) 



This book is founded on three Tyndall Lectures delivered before the Royal 

 Institution in the summer of 1914. The author is convinced that biological 

 chemistry cannot develop into a real science without the aid of physical 

 chemistry, and considers that the aversion to exact methods exhibited by bio- 

 chemists is due to their inability to appreciate such ideas as " experimental 

 errors " or " probable errors." Physical chemists have found that the biochemical 

 theories which are still accepted in medical circles are founded on an absolutely 

 unreliable basis and must be replaced by other notions agreeing with the 

 fundamental laws of general chemistry. 



The first chapter, which is introductory, contains, amongst other things, an 

 account of the graphical methods of presenting experimental results. The second 

 chapter is devoted to the discussion of the reaction velocity of a number of 

 biochemical enzyme actions, such as peptic digestion, the decomposition of 

 vibriolysin and so forth. It is shown that Schiitz's Rule, according to which 

 the action is proportional to the square root of the quantity of enzyme, holds good 

 until about 50 per cent, is digested, but after that the amount changed falls 

 short of the value calculated according to this rule. The author's experiments 

 have refuted the idea that the obedience to this law distinguishes organic 

 ferments from ordinary catalysers by showing that when a great excess of 

 ammonia acts on ethyl acetate exactly the same rule holds good until about 

 50 per cent, of the ammonia is used up by the formation of ammonium acetate. 

 The third chapter deals with the influence of temperature on reaction velocity, 

 and here again it is shown that processes in which enzymes, bacteria or other 

 living cells are concerned follow the same laws as ordinary chemical processes ; 

 the existence of an optimum temperature is conditioned by the thermolabile 

 nature of the substances concerned. The author refuses to accept Van 't HofPs 

 theory as to the reversibility of enzyme reactions, and subsequently in a rather 

 lengthy chapter on chemical equilibria as applied to toxins and antitoxins, 

 he develops the thesis that anti bodies do not act as enzymes or catalysers, but 

 in reality take part in the equilibrium. 



Although the book deals almost entirely with reactions of great importance 

 in medicine and physiology, it is of too technical a nature to appeal to either 

 doctors or physiologists, but it will convince the physical chemist that biological 

 phenomena are subject to the same fundamental laws as ordinary chemical 

 phenomena. 



While it is undoubtedly a very creditable achievement for the author to have 

 written this book in English, it cannot be denied that both the style and the 

 clearness would have gained in places by a little revision. 



P. H. 



