A Manual of the Chemistry of the Carbon Compounds

494 THE CHEMISTRY OF
Htemaglobin combines with many gases, forming peculiar unstable
compounds. Thus it absorbs oxygen, and assumes a brighfc-red
colour (arterial blood). When carbon monoxide is passed through
this solution the oxygen is given off, and the hsemaglobin combines
with the carbon monoxide, which again may be replaced by nitrogen
dioxide. It also combines with acetylene and hydrochloric acid.
Arterial blood, or a solution, heemaglobin saturated with, oxygen
gives an absorption spectrum containing two dark bands (Fig. 15,
Fia. 18.
No. 1), which, on saturating the liquid with carbon dioxide (venons
blood), are replaced by a single band as seen in No. 2. On shaking
venoua blood with air the two original lands make their appearance
again.
Heemaglobin contains in 100 parts:—
Carbon 54'2
Hydrogen 7*2
Nitrogen 16-Q
Oxygen , 21'5
Sulphur 0-7
Iron 0-4
100-0
Hamatin CJRygtfiJPe is produced, togother with a proteid,
when hseaiaglobin is treated with acids or alkalis. It is an amorphous
bluish-black mass, having a metallic lustre, and dissolving in
alkalis, but not in alcohol and water. It is also capable of yielding
two absorption-spectra by the action of oxygen and carbon dioxide;
these bands are seen in Fig. 15; N09. 3 and 4.