Chapter Blow a Cloud to Blue Devils of B by Brewer's Phrase & Fable

Blue Bottle A beadsman, a policeman; so called from the colour of his dress. Shakespeare makes Doll Tearsheet denounce the beadle as a “blue-bottle rogue.”

“You proud varlets, you need not be ashamed to wear blue, when your master is one of your fellows.”- Dekker: The Honest Whore (1602).

“I'll have you soundly swinged for this, you blue-bottle rogue.”- Shakespeare: 2 Hen. IV., act v. 4.

Blue Caps or Blue Bonnets. The Scotch.

“He is there, too, ... and a thousand blue caps more.”- Shakespeare: 1 Henry IV., ii. 4.

Blue-coat School Christ's Hospital is so called because the boys there wear a long blue coat girded at the loins with a leather belt. Some who attend the mathematical school are termed King's boys, and those who constitute the highest class are Grecians.
   Founded by Edward VI. in the year of his death. There are several other blue-coat schools in England besides Christ's Hospital.

Blue Devils or A fit of the blues. A fit of spleen, low spirits. Roach and Esquirol affirm, from observation, that indigo dyers are especially subject to melancholy; and that those who dye scarlet are choleric. Paracelsus also asserts that blue is injurious to the health and spirits. There may, therefore, be more science in calling melancholy blue than is generally allowed. The German blei (lead) which gives rise to our slang word blue or blucy (lead) seems to bear upon the “leaden down-cast eyes” of melancholy.