viii Preface 



There are occasions on which every sailor of the deep sea has to 

 ship a pilot. Mr A. V. Hill has brought me into those harbours 

 which are best approached through the, to me, unknown channels of 

 mathematics. T have to thank him and also Miss Dale for much 

 help with my proofs. 



In the preparation of this book my acknowledgments are due to 

 many friends and others for allowing me to reproduce their photo- 

 graphs or illustrations Mr C. G. Douglas (Figs. 115 119), Prof. 

 Durig(Figs. 127 a, 131 and 133), Dr Aggazzotti (Figs. 127 b and 132), 

 Dr Haldane and the Council of the Royal Society (Figs. 71, 72 and 

 73), Mr Hartridge and the Council of the Royal Society (Fig. 104), 

 Dr Lewis and the publishers of Heart (Fig. 105), Dr Krogh and 

 the publishers of the Skandinavisches Arch, fiir Physiologic (Figs. 

 98 and 99), Dr Rohde and the publishers of the Archiv fiir 

 experimentelle Pathologic mid Pharmakologie (Figs. 52 55), 

 Prof. Nuttall and the publishers of the Journal of Parasitology 

 (Fig. 2), and Dr Warburg (" Ueber Hemmung der Blausaurewirkung 

 in lebenden Zellen," H. S. Zeits. fiir pht/s. Chemie, Band 76, S. 331, 

 Strassburg, Karl J. Triibner), and to the Editor of the Journal 

 of Physiology for permitting the reproduction of many figures of 

 my own. 



Lastly, my thanks are due to certain Corporations who have 

 given me grants for research the Royal Society, the British 

 Association, the Fellows of King's College and the Commission for 

 the Study of the Biochemical Effects of High Climates and Solar 

 Radiation presided over by Prof. Pannwitz of Berlin. 



J. B. 



CAMBRIDGE, 



December 1913. 



