Gunpowder, or blasting powders, is slowly and gradually becoming part of the First Law world. At the start of the original trilogy, only the Gurkish have acquired solid knowledge of gunpowder. In The Union, the adepti in the University have only obtained samples of it from Kanta for study. However, blasting powder cames to sharp prominence in the Battle of Adua, where the Gurkish used it as an effective weapon against the city walls; a wall that would have stood a week of bombardment could be brought down in an hour.
As a result, the study of blasting powder in the University has became more prevalent. In fact, the study of science in general seems to have revived somewhat, with The Union seemingly emerging from the Middle Ages, and into the early Industrial Age. In The Heroes, the first primitive testing of cannons are performed by The Union, and a more advanced one is successfully field-tested in Red Country.