60 Messrs. Buckmaster and Gardner. Composition of [Jan. 9, 



In Table II we give similar data with the respiration of oxygen, the 

 samples of blood for analysis and those of alveolar air being taken during the 

 period of oxygen inhalation ; the alveolar air immediately after the blood 

 sample. 



On comparing these two tables, it will be seen that the average blood gases 

 in the two series of experiments are in close accord, indeed practically 

 identical. 



Average of Thirteen Experiments on Cats breathing Air and Oxygen. 



I 



j Air. 



Oxygen. 



Total gas 53-76 



Carbon dioxide 38 -43 



Oxygen > 14-22 



53 -79 

 38 -65 

 14 -94 



In some experiments blood was abstracted from the same animal when 

 breathing first air and subsequently oxygen. 



A contrast of these duplicate samples of arterial blood of animals breathing 

 air and oxygen is given below :— 



Air. 



Oxygen. 



co 2 . 



0.,. 



C0 2 . 



o 2 . 



47-84 



15 66 



45 -65 



18 -81 



33 -09 



15 -96 



26 -90 



12 -30 



33 -65 



15-29 



38 -28 



16 -62 



35 -76 



14-89 



33 09 



13-85 



37 -48 



15 -22 



32-83 



14 -82 



31 -77 



16-68 



37 -99 



16 -99 



It will be seen that, although the percentage of haemoglobin is practically 

 the same in the same pair of experiments, the oxygen in the blood is some- 

 times a little greater, sometimes less, when oxygen is inhaled, differences 

 which appear to be independent of the percentage of oxygen in the 

 alveolar air. 



The haemoglobin values in the several experiments are very variable in 

 cats. The theoretical oxygen capacity of cats breathing air, ascertained from 

 10 experiments in which the haemoglobin values were determined, was 

 17"15 c.c. per 100 c.c. of blood. Calculating from the average oxygen found, 

 14 - 22, the average percentage saturation of haemoglobin is about 83. 



In the case of animals breathing oxygen, the theoretical oxygen capacity 



