The deep blood-red color of solutions of ferric sulphocyanate has frequently been taken advantage of for the determination of small quantities of iron in river or spring water, in blood; in alloys, in alumcake, etc. The earliest method of this kind so far as I have been able to ascertain, is due to T. L. Herapath, who proposed to determine minute quantities of iron by the addition of potassium sulphocyanate to the acidified solution containing an unknown amount of iron, and also to a standard iron solution of known strength, the latter being then diluted until both showed the same tint.
Proceedings of the Iowa Academy of Sciences
©1893 Iowa Academy of Science, Inc.
"Some Peculiarties of Solutions of Ferric Sulphocyanate,"
Proceedings of the Iowa Academy of Science, 1(Pt. 4), 12-15.
Available at: https://scholarworks.uni.edu/pias/vol1/iss4/5