does anybody kno what blue mickey mouses are like bristol area ??? not sure of the size as i havent seen them but i kno of a reliable source??

Unless your mate has a gas chromatograph/mass spectrometer, all he could say from a simple reagent test was that there was some ket, but not what else was in them. There's a lot of nasty stuff that on its own wouldn't give any reaction to the usual test (Mandelin) that shows up ket. It's well known that dodgy pill producers will put a little bit of something "good" in otherwise skanky pills to fool reagent tests.

See Wikipedia: Pill testing