Does anyone know the name of the candy that has this powdery stuff inside that fizzes?!

I used to buy it all the time when I was a kid in 1960-70's and was just thinking about it. My brother called them Farts. They were like a hard candy with some sort of acidic powder in the middle..they were good. They must still be made as they were pretty popular in about 1969 or so. I always bought them at the penny candy store, there were like 2 for a nickel I think and later a nickel but then I don't remember what happened to them? Can't find Turkish taffy either, what is happening to this world?