Saint Petersburg Declaration of 1868

In 1863, the Russian Army had perfected a fulminating musketball that could explode when it hit a hard target and was designed to blow up powder magazines or ammunition wagons.

At the same time several similar projectiles for the same purposes were developed in America, the best one known being the Gardiner's Explosive Bullet, and both sides used them in the US Civil War, inflicting horrible wounds when aimed at people, and that, in turn, caused a public backlash against the weapon.

Predicting the disastrous effect of such a discovery on diplomatic relations with their neighbors, Russia decided to negotiate a ban on the development, creation, and use of such weapons before a grisly arms race commenced.

The Great Powers agreed to renounce, in case of war among themselves, the use "by their military or naval troops of any projectile of a weight below 400 grams (14 ounces avoirdupois), which is either explosive or charged with fulminating or inflammable substances."

The reason for the prohibition is explained as follows: such projectiles are small and just powerful enough to kill or wound only one man, and as an ordinary bullet will do for this purpose, there is no overriding need for using these inhuman weapons.