Note 42 — HISTORICAL INTRODUCTION.

The animal nature of the colouring matter of the blood was first pointed out by Dr. Wells, but Fourcroy and Vauquelin considered it to be owing to subphosphate of iron. Mr. Brande, in 1812, demonstrated the fallacy of this opinion, and proved, by satisfactory experiments, its title to be considered as a peculiar animal principle; the subsequent experiments of M. Vauquelin have confirmed Mr. Brande’s results.