Blue Caps

Regional drug slang for a formulation of mescaline
References in classic literature ?
Nine-tenths of the Heidelberg students wore no badge or uniform; the other tenth wore caps of various colors, and belonged to social organizations called "corps." There were five corps, each with a color of its own; there were white caps, blue caps, and red, yellow, and green ones.
He stooped a little, and with his tattered blue cap pointed under the carriage.
The accursed was already under the carriage with some half-dozen particular friends, pointing out the chain with his blue cap. Some half-dozen other particular friends promptly hauled him out, and presented him breathless to Monsieur the Marquis.
The sweet scents of the summer night rose all around him, and rose, as the rain falls, impartially, on the dusty, ragged, and toil-worn group at the fountain not far away; to whom the mender of roads, with the aid of the blue cap without which he was nothing, still enlarged upon his man like a spectre, as long as they could bear it.
So they opened the door and entered the house, where a little light-brown donkey, dressed in a blue apron and a blue cap, was engaged in dusting the furniture with a blue cloth.
A blue cap with a patent leather peak set well at the back of his yellow bush of hair gave him the aspect of a Norwegian sailor bored with the world after a thundering spree.
Contract award notice: Supply of 800 pieces (05006137) blue plastic tag holder key ring with metal ring (in bags of 100 units), 418llaaz blue caps or equivalent, Within an emt own classification system (spain-madrid: Tools)
"The prefects wore light blue caps with 'WGS' on them while we wore navy blue caps with light blue bands around them."
On a different note, just a point in resonse to a recent letter, it was Gene Vincent and the Blue Caps not Cats.
Snowmen in matching red or blue caps and scarves encircle the base.
Master diver Lucy Harrison, 25, was diving at Blue Caps Reef when she spotted the creature in the distance on Saturday.