58 CARBONIC ACID AND NITROGEN IN BLOOD. 



ordinary oxygen (0 2 ) in the air. (2.) Active or nascent oxygen (0), which never 

 can occur in the free state, but the moment it is formed acts as a powerful 

 oxidising agent and produces chemical compounds. It converts water into hydric 

 peroxide the N of the air into nitrous and nitric acids, and even CO into C0 2 , 

 which ozone does not. It certainly plays an important part in the organism. (3.) 

 Ozone (Os), which is formed by the decomposition of several molecules of ordinary 

 oxygen (0 2 ) into two atoms of 0, and the appropriation of each of these atoms by a 

 molecule of undecomposed oxygen. It is oxygen condensed to of its volume. 



38. Carbonic Acid and Nitrogen in Blood. 



II. Carbonic Acid. In arterial blood there are about 30 volumes per 

 cent, of C0 2 (at 0C. and 1 metre pressure Setschenow); but in venous 

 blood the amount is very variable ; e.g., in the venous blood of passive 

 muscles there are 35 volumes per cent. (Sczelkow), while in the blood 

 of asphyxia there may be 5 2 '6 volumes per cent. The amount of C0 2 

 in the lymph of asphyxia is less than that in the blood (Buchner, 

 Gaule). 



The C0 2 in the entire mass of the blood may be extracted from it or 

 completely pumped out, but during the process of evacuation, or removal 

 of the gas, a new property of the red blood-corpuscles is produced, 

 whereby they assume the function of an acid and thus aid in the chemical 

 expulsion of the C0 2 . This acid-like property of the red corpuscles 

 occurs especially in the presence of O and heat. 



(A.) The C0 2 in the Plasma. The largest portion of the C.0 2 belongs to 

 the plasma (or serum) and it appears all to be in a state of chemical 

 combination. Serum takes up C0 2 quite independently of pressure, 

 hence it cannot be merely absorbed. A certain part of the CO 2 can be 

 removed from the serum (plasma) by the torricellian vacuum, while 

 another part is obtained only after the addition of an acid. [This is 

 called the " fixed " C0 2 , while the former is known as the " loose " 

 00,] 



The union of C0 2 in the serum may take place in the following 

 ways : 



(1.) C0 2 is united to the soda of the plasma in the form of " sodic 

 carbonate." This portion of the C0 2 can only be displaced from its 

 combination by the addition of an acid. (In depriving blood of its 

 gases the red corpuscles play the rdle of an acid.) 



(2.) A portion of the C0 2 is loosely united to sodic carbonate in 

 the form of sodic bicarbonate; the carbonate takes up 1 equivalent of 

 C0 2 ; Na 2 C0 3 +C0 2 + H 2 = 2 NaHC0 3 . This C0 2 may be pumped out, 

 as in the process the bicarbonate splits up again into the neutral 

 carbonate and CO 2 , 



