Research new sulphur purification methods

Research new sulphur purification methods is an upgrade in Cossacks 3, available at the Academy.

Background
The low effectiveness of early firearms was partly due to detrimental impurities. In time, the progress of chemistry reduced the percentage of impurities in one of the powder ingredients - sulphur - and thus improved gunpowder combustion efficiency.

Effect

 * Fire power +15%