44 CARBON DIOXIDE AND NITROGEN IN BLOOD. 



blue by ozone. If some tincture of guaiacum be added to turpentine there is no reaction, but on 

 adding a drop of blood a deep blue colour is immediately produced, i.e., blood takes the ozone 

 from the turpentine and conveys it at once to the dissolved guaiacum, which becomes blue. It 

 is immaterial whether the Hb contains O or not. 



(2) It is also asserted that haemoglobin acts as an ozone-producer, i.e., that it can convert the 

 ordinary .0 of the air into ozone. Hence the reason why red blood-corpuscles alone render 



fuaiacum blue. This reaction succeeds best when the guaiacum solution is allowed to dry on 

 lotting-paper, and a few drops of blood (diluted 5 to 10 times) are poured on it. That the Hb 

 forms ozone from the surrounding 0, is shown by the fact that red blood-corpuscles containing 

 carbonic oxide cause the blue colour ( Kit-hue and ScJiolz). According to Pfiiiger, however, these 

 reactions only occur from decomposition of the Hb, so that on this view the blood-corpuscles 

 cannot be regarded as producers of ozone. 



Sulphuretted hydrogen is decomposed by blood (as by ozone itself) into sulphur and water. 

 Hydric peroxide is decomposed by blood into and water [but this reaction is prevented by the 

 addition of a small amount of hydrocyanic acid (Schonbein)]. Crystallised Hb does not do this, 

 and H._,0 2 may be cautiously injected into the blood-vessels of animals. This would show that 

 unchanged Hb does not produce ozone. 



Various Forms of Oxygen. There are three forms of oxygen : (1) The 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 COo, which ozone does not. It certainly plays an important part in the organism. 

 (3) Ozone (0 3 ), which is formed by the decomposition of several molecules of ordinary oxygen 

 (O s ) into two atoms of 0, and the appropriation of each of these atoms by a molecule of unde- 

 com posed oxygen. It is oxygen condensed to of its volume. 



38. CO, AND N IN BLOOD. IT. Carbon Dioxide. In arterial blood there 

 are about 30 volumes per cent, of C0 2 at C. and 1 metre pressure (Setschenoiv) j 

 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 52*6 volumes per cent. The C0 2 in the lymph of asphyxia is less 

 than that in the blood (Bucluier, Gaule). The C0 2 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 CO,. 

 This acid-like property of the red corpuscles occurs especially in the presence of O 

 and heat. 



(A) The CO, in the Plasma. The largest portion of the C0 2 belongs to the plasma 

 (or serum), and it all appears to be in a state of chemical combination. Serum 

 takes up CO, quite independently of pressure, hence it cannot be merely absorbed. 

 A certain part of the C0 2 can be removed from the serum (plasma) by the 

 Torricellian vacuum, while another part is obtained only after the addition of an 

 acid. [The latter is called the " fixed " C0 2 , while the former is known as the 

 " loose " CO,.] The C0 2 in the serum existsln the following conditions : 



(1) CO^ is united to the soda of the plasma in the form of "neutral sodic 

 carbonatp. ' This portion of the CO, can only be displaced from its combination 

 by the addition of an acid. (In depriving blood of its gases the red corpuscles play 

 the role of an acid.) 



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

 hvarbonate ; the carbonate takes up 1 equivalent of C0 2 ; Na.,C0 3 + C0 2 + H 2 a 

 2NaHCO. } . This C0 2 may be pumped out, as in the process the bicarbonate splits 

 up again into the neutral carbonate and C0 2 . 



Preyer has objected to this view on the ground" that blood is alkaline in reaction, whilst all 

 solutions that contain CO., m a state of absorption, or loose chemical combination, are always 

 acid. Pfluger and Zuntz showed that blood, after being completely saturated with CO., still 

 remains alkaline. ^* 2 ' 



As the bicarbonate only gives up its C0 2 very slowly in vacuo, while blood gives off its CO, 

 very energetically perhaps the soda, united with an albuminous body, combines with the Co! 

 and forms a complex compound, from which the C0 2 is rapidly given off in vacuo. 



(3) A minimal portion of the CO, may be" chemically united with neutral sodic 



