220 Dr. W. Marcet. History of the Interchange of 



oxygen absorbed, and ratios (under the form of means), together 

 with their respective temperatures : 



Means . . 11'5 



13-4 

 13'5 



13'4 



14-4 

 14-4 

 14-4 

 14-4 



14-4 



16-3 



16-3 



Of coarse it cannot be expected, in a work of this kind, that tracings 

 will be perfectly regular ; hence in the tracing for oxygen consumed 

 we observe a slight abnormal rise between 14'4 and 16 0< 3. This is 

 probably owing to the weather being cold outside ; the experiment was 

 done on the 24th of February ; the maximum temperature of that day 

 in the open air was 9 C. (Wimbledon Park), and the body was partly 

 under this cooling influence, although the temperature of the labora- 

 tory, at University College, heated with hot-water pipes, was 16'3. 

 The tracing for carbonic acid produced also exhibits irregularities, 

 but the curves show distinctly that, at all events in my case, changes 

 of temperature exert a very positive influence on the interchange of 

 the pulmonary gases. 



If the temperatures of the atmosphere in which the experiments 

 are made be divided into two groups, one group including the lowest 

 and another the highest, and a table constructed, into which the 

 carbonic acid produced and oxygen absorbed are entered together 

 with their corresponding temperatures, this table will be as 

 follows : 



