DR. DAVY*S ACCOUNT OF SOME EXPERIMENTS ON THE BLOOD. 



287 



cocks closed. The night, that of the 23rd of January, was severely cold ; at 11 

 o'clock the following morning the temperature of the room was only 45° ; now on 

 turning the stop-cock of the bent tube the water rose in it to the extent of about one- 

 eighth of a cubic inch. 



Twenty-four cubic inches of the mixed arterial and venous blood of the Sheep, 

 collected and prepared with similar precautions, were divided into two portions of about 

 twelve cubic inches ; one was agitated in the double-mouthed bottle with hydrogen 

 after the introduction of a little milk of lime, the other without this addition. The 

 result in each instance was the same ; on opening the stop-cock, after the agitation, 

 the water rose a very little in the bent tube, about one-twentieth of a cubic inch. 



The results of some of the trials already described on the action of oxygen on venous 

 blood, both pure and mixed with azote, in the form of common air, are very con- 

 sistent with those just detailed on hydrogen. Previously to stating some other re- 

 sults in quest of fresh evidence on the same subject, it may be advisable to notice 

 particularly the power which blood possesses of absorbing carbonic acid. 



From experiments which I made on blood and serum in 1824 and 1828*, I in- 

 ferred that each is capable of absorbing about an equal volume of this acid gas. I 

 now find that when pure carbonic acid gas is brought in contact with blood or serum 

 over mercury, and moderately agitated under ordinary atmospheric pressure, that 

 the absorption of gas exceeds the volume of the fluid, both in the instance of blood 

 and serum. The results of some experiments are exhibited in the following Table. 

 The majority of them were obtained between a temperature of 40° and 45° ; the three 

 last at about 51°. When the venous and arterial blood, and the serum tried, were 

 from the same animal, the numbers expressing the results are entered in the same 

 line. 



Volume of carbonic acid gas absorbed by 100 parts of blood and serum. 



* Philosophical Transactions for 1824. Edinburgh Medical and Surgical Journal, vol. xxx. 



