Respiration. 2Q 



but that, as the air was always changing, it never had time to 

 obtain as much carbonic acid as the blood would give up, and 

 so a continual stream of carbonic acid passed from the blood 

 to the air in the lung. 



But he must pause, for whilst many distinguished physio- 

 logists would endorse such a statement, there were others who 

 considered that they were confronted at that point with a 

 paradox of life such as he had already mentioned; that in the 

 ordinary way after the blood has given up its quotum of 

 carbonic acid the living wall of the lung exerts an influence on 

 the blood which no dead membrane could exert, and makes the 

 blood concede yet further stores of carbonic acid to the air, 

 thus enormously increasing the efficiency of the respiratory 

 apparatus. The point is one of great interest to physiologists, 

 and it is one on which much careful work has been done. 

 While the matter remains unsettled it would ill befit him to 

 express an opinion upon it, in view of the fact that some of the 

 most recent and telling researches on the subject have been 

 those of Dr. John Haldane and Professor Lorrain Smith in 

 the laboratory of Queen's College, Belfast. 



Professor Lorrain Smith said their Secretary had asked him 

 to move a vote of thanks to Mr. Barcroft for his interesting 

 lecture, but he would preface his remarks by a promise to and 

 no more details to the many facts Mr. Barcroft had put before 

 them. He himself had followed the lecture with the greatest 

 interest, and he was sure this had also been done by everyone 

 present. As one whose duty it was to lecture and experiment 

 at the same time, Mr. Barcroft had managed to get through a 

 subject which was perplexity itself with wonderful rapidity. 

 The success with which he had carried out the experiments at 

 the end of the bench, where he had been engaged analysing 

 the blood from oxygen, was remarkable. It was not so very 

 long ago since it took a large part of a day to carry out an 

 experiment of that sort, but Mr. Barcroft had shown them that 

 night that this observation can now be carried out with ihe 



