Gases of the Blood 605 



Experiment CLXXIX. July 5. 76.5 cm. Dog weighing 10 k. 



Drew from the right carotid 35 cc. of very red blood; 38 respir- 

 ations, with little howls .... A 



3:25, put into the apparatus. 



3:45, pressure 30.5 cm., struggles, howls. At 3:55, pressure 24.5; 

 the gas machine stops. 



4:05, pressure 38 cm.; machine started again; 26 respirations, quiet. 



4:12, 26.5 cm.; 60 respirations, interrupted by hiccoughs; at 4:26, 

 19.5 cm.; 74 respirations, also with hiccoughs. 



4:30, pressure 18 cm.; drew 35 cc. of very dark blood . . . B 



4:42, pressure 17 cm.; 80 respirations; drew 35 cc. of very dark 

 blood . . . . C 



Opened the cock; at 4:55, the pressure had risen to 26 cm.; it was 

 maintained there, and at 5: 10, 35 cc. of dark blood drawn . . . D 



5:13, returned to normal pressure. 



6:00, took 35 cc. of blood, very red . . . E 



Blood A (76 cm.) contains per 100 volumes: O. 20.8; CO* 46.1 



Blood B (18 cm.) contains per 100 volumes: O 7.6; CO 12.9 



Blood C (17 cm.) contains per 100 volumes: Ch- 7.1; CO2 11.9 



Blood D (26 cm.) contains per 100 volumes: O. 9.2; CO. 13.7 



Blood E (76 cm.) contains per 100 volumes: O? 20.8; CO. 40.5 



When, after having followed the preceding experiments, we 

 examine Table X, which summarizes them and in which they are 

 arranged in the order of decompression, one of the first facts to 

 attract our attention is the remarkable variation presented by the 

 figures in Columns 3 and 4, which express the quantities of oxygen 

 and carbonic acid gas contained at normal pressure in 100 cc. of 

 blood. The variations for oxygen (setting aside Experiment 

 CLXXIV for reasons which I shall specify shortly) were from 16.9 

 to 22.6; those of carbonic acid, from 29.1 to 48.4. I should note that 

 there is no proportion, either direct or inverse, between the in- 

 creases or diminutions of these two gases, so that the variations of 

 the total (Col. 5) , which were from 48.2 to 67.8, are not the expres- 

 sion of any distinct law. 



The explanation of these variations cannot be found in the 

 details of the experiments. All my dogs were in good health, fed 

 on the same diet and at the same length of time before the experi- 

 ment; I took care, as I said, to draw blood from them during a quiet 

 period: they were, in short, as similar as possible. I am therefore 

 led to believe that these results agree with the true state of things 

 and that there are important differences between individuals in the 

 oxygen content of the arterial blood, although all circumstances 

 are similar. Furthermore, these variations are quite as apparent 

 in the tables of analyses published by other authors; it would be 

 a real delusion to get rid of them by getting some sort of an average. 



