ferric subsulfate (Monsel's solution)

Basic ferric sulfate solution. Fe4(OH)2(SO4)5. Prepared from FeSO₄ & HNO3. Reddish brown liquid. Almost odorless. Acidic to litmus paper. Light-sensitive. Stryptic. Astringent. Uses: topical coagulant to control bleeding during minor surgical procedures.

References

Merck Index, IIth ed, Merck & Co, Rahway NJ, 1989 # 4078