Vintage Sylvania Flash Bulbs For Cameras

There are two boxes with Sylvania flash bulbs for old cameras. Each box is supposed to have 12 bulbs. One box has 12. The other box has eleven bulbs. They are so old the boxes have aged. These are Sylvania flash bulbs with blue dot. Back in the day people knew what that meant. Today I have no idea what the blue fit means or how to use the bulbs. My cameras all have built in flash. I remember my mother taking photos and the flash was bright.