saltpeter

[baybled]

what is saltpeter?

[wildwood]

potassium nitrate

[melandraf]

They put it in ciggies to keep 'em burning.

[thekraut]

If you want to make gunpowder then any first group metal nitrate will do. but anything below K will be a little bit difficult to come by. Anyway, NaNO3 works just as well as KNO3

[tomd]

Saltpeter also used to be used in slow burning fuses, mix it with a little water to make a heavy paste & paint it across your patio. Light one end and in about an hour it'll have got to the other. Also used in making glass (melt with sand) & gunpowder.