Notices respecting JSeio Boohs. 38^> 



detected. And lastly, in conjunction with Dr. Phillips, he showed 

 that gravitation is independent of temperature ; at least to within 

 1 part in a thousand-million between 15° and 100° 0. 



This brief summary has referred only to investigations of 

 physical interest. The papers here reprinted include one on the 

 Drunkenness statistics of the large towns in England and Wales ; 

 and one on a comparison of the fluctuations in the price of wheat 

 and in the cotton and silk imports into Great Britain ; and also 

 twenty-five addresses and general articles. In all, seventy com- 

 munications are reproduced. 



Poynting was above all an experimental philosopher. Although 

 he had a theoretical equipment of a high order he was somewhat 

 afraid of theoretical results unless well tested experimentally. 



The present volume is a memorial one edited by Drs. Shakespear 

 and Guy Barlow. It contains biographical notices by Sir J.Thomson, 

 Sir O. Lodge, and Sir Joseph Larmor. 



It is a worthy memorial ; it will make better known to all the 

 work of a man who was one of the least assertive of men ; but who 

 by his quiet and pertinacious labours (with a body enfeebled by 

 disease) has enriched the world. 



The Concept of Xature. Tarner Lectures delivered in Trinity 

 College. November 1919. By A. N. Whitehead. Cambridge 

 University Press. 



Professor Whitehead asks us to regard this book as a com- 

 panion to his recently published Enquiry concerning the Principles 

 of Natural Knoivledge (see Phil. Mag. June 1920). The two books 

 are independent, but they supplement one another. It is quite 

 clear why he wishes us to do so. In the Enquiry he accepted, 

 not uncritically, the principle of relativity, and particularly the 

 expression given to it by Minkowski in his concept of a four- 

 dimensional universe constituted of events. The purpose of the 

 Enquiry was to demonstrate the fundamental character of the 

 event, to show hoAV events are related and measurable, how objects 

 are derived from them and to settle in the form of a definition 

 what an event and what an object is. His book, however, was 

 hardly published before we were all discussing the new general 

 relativity of Einstein. It is not surprising therefore that Pro- 

 fessor Whitehead has taken the opportunity of the Tarner 

 Lectures to make his own position in regard to the generalized 

 principle clear. 



Without being at all unreceptive to the new theory, and while 

 accepting its particular applications, the new formula for gravi- 

 tation for example, he is very anxious to dissociate himself from 

 the extremist interpretation. His keen philosophic vision warns 

 him lest a position of absolute negativity towards independent 

 objective reality should bring upon physical science a similar 

 impasse to that which Hume's scepticism brought upon philosophy. 



