(a) Colloidal antimony → Used in treatment of Kala-azar→ (III)(b) Argyrol (colloidal silver) → Used as an eye lotion→ (I)(c) Colloidal gold → Used for intramuscular injections (tonic for nervous disorders)→ (II)(d) Milk of magnesia → Used for stomach disorders (antacid/laxative)→ (IV)