The document describes the isolation and analysis of menthol from peppermint leaves. Menthol is obtained through steam distillation or solvent extraction of dried peppermint leaves. It is identified through its melting point of 41-43°C and chemical tests. Menthol can be analyzed using techniques like thin layer chromatography, high performance liquid chromatography, gas chromatography, and infrared spectroscopy. Its main chemical constituent is menthol, which makes up 78% of the volatile oil.