Why is a drying agent kept inside a gold-leaf electroscope?

Explanation

Though dry air is a good insulator, moist air conducts electricity moderately. If a charged body finds itself in moist air, charges will leak and ultimately gets discharged. Hence, due to presence of moist air inside a gold-leaf electroscope, the diver gence of the leaves will gradually decrease. To avoid this unwanted condition, drying agents (hygroscopic substances) are kept inside a gold-leaf electroscope.