The blood is coloured red by haemoglobin in blood corpuscles.
These corpuscles may break down in the blood vessels, and their colouring material (haemoglobin) is set free in the serum.
It is very poisonous, uniting with the haemoglobin of the blood to form carbonyl-haemoglobin.
Lxiii.; On the Distribution of Assimilated Iron Cornpotrnds other than Haemoglobin and Haematins, in Animal and Vegetable Cells, Quart.
They occupy and destroy the red corpuscles, converting the haemoglobin into melanin; they multiply in the blood by sporulation, and produce accessions of fever by the liberation of a toxin at the time of sporulation (Ross).