Blue Caps

Regional drug slang for a formulation of mescaline
References in classic literature ?
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.
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.
BCCI will pick at least five new-caps along with Kedar Jadhav, who is being expected to return with blue caps again in Nidhas Trophy
Tenders are invited for Quotations Are Invited For Supply Of Black Colour Folding Umbrella And Light Blue Caps At Beml Regional Office, Ranchi
The PQRs wear dark green caps while Civil Defence Razkars use dark navy blue caps.
Officers on horseback, bikes and on foot became a familiar site across the city centre over the weekend, with police all wearing light blue caps.
Police officers were seen across Cardiff city centre Saturday - on bikes, on foot and on horseback, wearing what now appear to be signature blue caps.
The blue caps each carry the famous Three Lions embroidered in white along with the words "The Football Association".