80 CARBON DIOXID AND NITROGEN IN THE BLOOD. 



Oil of turpentine that has been exposed to the air for a considerable time 

 always contains ozone. Among reagents for ozone are potassium-iodid paste, 

 which becomes blue, as the ozone releases the combination of iodin and potassium, 

 and the iodin causes the starch-paste to become blue; further, freshly prepared 

 solution of guaiac-resin in alcohol, which also is made blue by ozone. A solution 

 of guaiac is dropped in water, the resin forming a milky precipitate, and oil of 

 turpentine is added. At first no reaction occurs, but if blood or hemoglobin be 

 added, with agitation, a bluish discoloration appears, that is, the blood takes the 

 ozone from the oil of turpentine and conveys it to the guaiac-resin. 



It has been stated that hemoglobin acts as an ozone-producer; that is, it is 

 capable of generating ozone from the inactive oxygen of the air with which it 

 comes in contact. For this reason, red blood-corpuscles alone also cause guaiac 

 to become blue. The reaction is most successful if the solution of guaiac is per- 

 mitted to dry upon blotting-paper and then several drops of blood diluted from 

 5 to 10 times are added. That under these circumstances the condition is one 

 of stimulation of the surrounding oxygen through the hemoglobin, is shown by 

 the observation that even red blood-corpuscles containing carbon monoxid bring 

 about the blue coloration, naturally not when the extraneous oxygen of the air is 

 excluded. According to Pfluger these reactions take place only with decompo- 

 sition of the hemoglobin, and for this reason it is believed that the blood-corpus- 

 cles as such do not act as producers of ozone." 



Also hydrogen sulphid is decomposed by the blood, as by ozone itself, into 

 sulphur and water. Hydrogen dioxid likewise is decomposed by the blood into 

 oxygen and water. This can be prevented by the addition of a small amount of 

 hydrocyanic acid. Crystallized hemoglobin does not bring this result about, and 

 hydrogen dioxid can be cautiously injected into the veins of animals. From this 

 it would appear that unaltered hemoglobin has no ozone-producing effect. 



There are three varieties of oxygen: (i) Ordinary or inactive oxygen (O 2 ) , 

 as, for instance, that of atmospheric air. (2) Active or nascent oxygen (O), which 

 can never occur in the free state, but which on its development at once enters 

 into chemical combination as a most powerful oxidizing agent. This is capable 

 of oxidizing water into hydrogen dioxid, the nitrogen of the air into nitrous and 

 nitric acids, and also carbon monoxid into carbon dioxid which ozone is not 

 capable of doing. This gas certainly plays an important role in the organism. 

 (3) Ozone (O 3 ) forms through the breaking up of certain molecules of ordinary 

 oxygen (O 2 ) into two atoms each (O), and union of each of these atoms with an 

 undecomposed molecule of oxygen. Ozone is a form of oxygen compressed to 

 two-thirds of its volume. 



CARBON DIOXID AND NITROGEN IN THE BLOOD. 



Carbon dioxid is present in arterial blood in from 34 to 38 volumes 

 per cent., at a temperature of o C. and a pressure of i meter; in 

 venous blood on the average in 9.2 volumes per cent, more than in 

 arterial blood, varying greatly in accordance with the situation and 

 the circulatory conditions. The total amount of carbon dioxid in 

 the blood does not equal even one-half of that which the blood 

 would actually be capable of taking up. Thus, the blood after asphyxi- 

 ation may contain as much as 52.6 volumes per cent. The amount of 

 carbon dioxid in the lymph after asphyxiation is less than that in the 

 blood. The carbon dioxid can be completely pumped out of the total 

 volume of blood without the formation of acids in the process of evac- 

 uation in consequence of decomposition of the constituents of the 

 blood which might take part in driving out the carbon dioxid. 



The Carbon Dioxid of the Plasma or the Serum. 



(a) This is absorbed in smallest part simply by the blood-plasma. 



(b) The largest part of the carbon dioxid is combined chemically 

 with the blood-plasma, independently of the pressure. This combi- 

 nation may take place in the following manner: 



i. A portion of the carbon dioxid is loosely combined with sodium carbonate, 

 forming sodium bicarbonate, one equivalent of carbon dioxid being taken up by 



