Note 37 — Chapter III · (continued 3)

“On the Reduction and Oxidation of the Colouring-matter of the Blood” (“Proc. of the Royal Soc.” vol. xiii. p. 355). The oxidising solution is made as follows:—To a solution of proto-sulphate of iron, enough tartaric acid is added to prevent precipitation by alkalies. A small quantity of this solution, made slightly alkaline by ammonia or carbonate of soda, is to be added to the weak solution of blood in water.