RESPIRATION ix 



that the almost incredible delicacy of the regulation of breathing 

 was discovered; and human experiments have revealed to us in 

 other ways how rough many of the experiments on animals, or 

 on "preparations" from the bodies of animals, have been. Organic 

 regulation, with its all-important relations to practical medicine 

 and surgery, was often entirely overlooked. I hope that the book 

 may contribute towards establishing human physiology in its 

 rightful place, which has been usurped too long by experiments 

 on fragments of frogs and other animals, or on the mere super- 

 ficial physical and chemical aspects of bodily activity. 



I wish to offer my sincere thanks to Yale University for the 

 honor it has done me in inviting me to give the Silliman Lectures. 

 Between Oxford and Yale Universities there is a traditional 

 association, and to me in particular the association stands for 

 friendship, hospitality, and community of ideas. My only regret 

 is that in coming to Yale to lecture on the physiology of breathing 

 I seemed to be doing what an Englishman calls bringing coals 

 to Newcastle, since I had to refer so frequently to the results 

 reached at Yale by Professor Yandell Henderson and his pupils. 



The book sums up the results of more than twenty years of my 

 own experimental work, thought, reading, and discussion. To the 

 old pupils and other friends who have worked and thought with 

 me, including friends in the mining and engineering professions 

 and in the Navy and Army, I wish to express my debt. Their 

 names are often quoted in the text, but I should like to say how 

 much I have been aided more particularly by Professor Lorrain 

 Smith, Professor Pembrey, Professor Boycott, Commander Da- 

 mant, Mr. Mavrogardato, Dr. Priestley, Dr. Douglas, Professor 

 Meakins, and my son. In connection with the Pike's Peak Scien- 

 tific Expedition, the results of which occupy such a prominent 

 place in the book, Dr. Douglas and I had the great advantage 

 of being associated with Professor Yandell Henderson and another 

 Yale graduate, Professor Schneider of Colorado Springs. The 

 book owes much to the talks we had on the Peak in the summer 

 evenings when our work was over and the lights were twinkling 

 over the prairie far below from Denver to Pueblo. 



Readers will easily see how many gaps remain to be filled up. 

 To fill these gaps the observations and experiments required are 

 not yet available. The words of Hippocrates are as true now as 

 when he wrote them more than two thousand years ago :6/3ibs flpa- 



Xvs, rj & Ttyy-n ^ K P^ 

 OXFORD, MAY 1920. 



