Alchemist's Alchohol (3.5e Equipment)
From D&D Wiki
Highly explosive alcohol in a wide cloth mouth vial. When a thin layer is spread, it makes an object very flammable and makes an extremely quick-lighting(30ft/round) fuse. One bottle covers 100 square feet and evaporates in 10 rounds. If stuck on an arrow (fits on large, medium, and small arrows) and the cloth is lit, the vial will explode when shattered. This deals 2d6 fire damage to the target regardless of miss or hit, and deals 1d6 piercing and slashing damage from shattered glass and 2d6 more fire damage on hit. On a critical, it deals critical arrow damage and deals double fire and shatter damage.
One bottle is 100gp.