INDIVIDUAL CONSTITUENTS OF THE BLOOD. 8l 



the simple carbonate: CO 3 Na 2 -f CO 2 4- H 2 O =2CO 3 NaH. In this way considerable 

 amounts of carbon dioxid may be bound. As the sodium bicarbonate releases the 

 carbon dioxid but slowly in a vacuum, while blood releases it with violence, it 

 must be borne in mind that perhaps sodium combined with a proteid (serum- 

 globulin alkali) contains the carbon dioxid in a complex combination, from 

 which it readily separates in a vacuum. 



2. A minimal portion of the carbon dioxid of the plasma might be combined 

 chemically with neutral sodium phosphate: One equivalent of this salt may 

 combine with one equivalent of carbon dioxid, so that acid sodium phosphate 

 and acid sodium carbonate result: PO 4 Na 2 H + CO 2 + H 2 O = PO 4 NaH 2 + CO 3 XaH. 

 In the process of evacuation the carbon dioxid escapes, with the formation of 

 neutral sodium phosphate. As, however, the sodium phosphate formed in blood- 

 ash has resulted almost wholly from the combustion of lecithin and nuclein, only 

 the small amount of this salt already present in the plasma can be taken into 

 consideration. 



The Carbon Dioxid in the Blood-corpuscles. 



The erythrocytes also contain carbon dioxid in loose chemical com- 

 bination. In denbrinated human blood 31.12 volumes per cent, of 

 carbon dioxid have been found in the serum, and only 4.5 in the blood- 

 corpuscles. The combination of the carbon dioxid is effected in part, 

 through the hemoglobin, therefore through the formation of carbohem- 

 oglobin, in part from the globulin-alkali combinations of the erythro- 

 cytes. The leukocytes also combine with carbon dioxid in accordance 

 with the character of the constituents of the serum, and in about the 

 proportion of from T ^ to \ of the absorptive power of the serum. 



According to Bohr there are three varieties of carbon-dioxid combination 

 with hemoglobin, which, while closely resembling one another, take up different 

 amounts of carbon dioxid namely 1.5, 3 and 6 cu. cm. of carbon dioxid respec- 

 tively to i gram of hemoglobin, at the same partial pressure for the carbon dioxid 

 and at the same temperature. Spectroscopically, carbon-dioxid hemoglobin re- 

 sembles reduced hemoglobin, except that its absorption-band lies somewhat nearer 

 the violet, and it absorbs more light in the green. Hemoglobin can take up oxy- 

 gen and carbon dioxid at the same time, and each independently of the other. 

 Therefore it is probable that oxygen and carbon dioxid unite with different con- 

 stituents of the hemoglobin. 



The amount of carbon dioxid in the blood is diminished by alcoholic intoxica- 

 tion, while it is increased by inhalation of ether, w r hich reduces the amount of 

 oxygen. Subcutaneous injection of morphin or chloral diminishes the amount 

 of oxygen. After administration of iodin, mercury, sodium oxalate and nitrate 

 there is a reduction in the amount of carbon dioxid in arterial blood. The same 

 result is brought about in the blood of animals by injection of peptone into the 

 veins, and also in the febrile state on account of the lessened alkalinity of the 

 blood. 



Nitrogen is present in the blood in the proportion of from 1.4 to 1.6 

 volumes per cent, in a state of simple absorption. 



For every 100 parts of nitrogen there are 2.1 parts of argon, which, however, 

 is present only in the plasma. The blood contains more nitrogen when the 

 number of erythrocytes is larger than when the number is smaller and when the 

 blood is lake-colored. Jolyet and Sigalas believe, therefore, that the erythrocytes, 

 like solid bodies, absorb nitrogen at their surface. On standing outside the body,, 

 the blood yields small amounts of ammonia, particularly with access of oxygen 

 and application of heat, perhaps in consequence of decomposition of an as yet 

 unknown ammonium-salt. 



ESTIMATION OF THE INDIVIDUAL CONSTITUENTS OF THE 



BLOOD. 



Estimation of the Water and of All of the Solid Constituents of the Total Blood 

 or of the Serum. About 5 grams of serum or defibrinated blood are evaporated 

 in a crucible of known weight over a water-bath and dried in a drying chamber 

 6 



