198 
HAEMOGLOBIN. 
blood-colouring matter, it is advisable to consider its elementary com- 
position, and to ascertain how the results of chemical analysis bear on 
the question as to haemoglobin being a definite chemical individual, its 
composition being invariable. 
Hemoglobin is a compound of carbon, hydrogen, nitrogen, sulphur, 
iron, and oxygen. The crystals of haemoglobin contain water of crystal- 
lisation, which varies considerably in amount in the hemoglobin of 
different animals. When ignited, pure haemoglobin obtained from 
mammalian blood yields an ash composed entirely of ferric oxide ; the 
haemoglobin of birds and fishes, and probably of all animals with 
nucleated corpuscles, yields on ignition an ash which, in addition to 
Fe 2 3 , contains phosphoric anhydride (P 2 5 ), derived in all probability 
from nuclein contained in the corpuscles. 1 
The earlier analyses of oxyhemoglobin made by C. Schmidt 2 and 
by Hoppe-Seyler 3 exhibited results which appeared to indicate that 
crystallised oxyhemoglobin is a body of constant composition. From 
the analyses of these two observers, and his own determinations of the 
iron and sulphur in crystallised oxyhemoglobin, Preyer deduced the 
following as the mean percentage composition of oxyhemoglobin : — 
In 100 Parts. 
C 
H 
N 
Fe 
S 
o 
54-00 
7-25 
16-25 
0-42 
0-63 
21-45 
100-00 
On the assumption, which a large number of facts have since shown 
to be almost certainly correct, that the molecule of hemoglobin contains 
one atom of iron, Preyer assigned to it the empirical formula C 600 H (J00 
N 154 FeS 3 O 170 , the molecular weight being 13,332. 
Analysis of Oxyhemoglobin dried at a temperature above 100° 6V 1 ' (Hoppe-Seyler). 
Water of Crystallisa- 
Oxyhemoglobin of 
tion in the Crystals 
which had been 
dried in vacuo. 
C. 
H. 
N. 
0. 
S. 
Fe. 
P 2 5 . 
Dog . . . 
3-4 per cent. 
53-85 
7-32 
16-17 
21-84 
0-39 
0-43 
Goose . 
7 ,, ,, 
54-26 
7-10 
16-21 
20-69 
0-54 
0-43 
0-77 
Guinea-pig . 
6 ,, ,, 
54-12 
7-36 
16-78 
20-68 
0-58 
0-48 
Squirrel 
9 
54-09 
7-39 
16-09 
21-44 
0-40 
0-59 
1 Y. Inoko, " Einige Bemerkungen ueber phosphorhaltige Blutfarbstoffe," Ztschr. f. 
physiol. Chem., Strassburg, 1894, Bd. xviii. S. 57. 
-"Analyse der Blutkrystalle," in Bottcher's monograph, " Ueber Blutkrystalle," 
Dorpat, 1862. 
3 "Beitrage zur Kenntniss des Blutes des Menschen und der Wirbelthiere ; Zusammen- 
setzung der Farbstoftkrystalle des Meerschweinchen- und des Hunde-bhites," Med. Chem, 
Untersuch., Berlin, 1868, S. 186 et seq. 
