The blood pigment haemoglobin is a compound which can be split by diverse methods into its constituents, pigment and protein. – Hans Fischer
In cases of porphyria, a minor disease, the patient excretes large quantities of porphyrins. – Hans Fischer
Coproporphyrin in particular is widespread; traces are present in normal urine and also in yeast. In special cultures, yeast can be made to produce considerable quantities of coproporphyrin. – Hans Fischer
