E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Prooshan Blue (My).
A term of great endearment. After the battle of Waterloo the Prussians were immensely popular in England, and in connection with the Loyal True Blue Club gave rise to the toasts, The True Blue and the Prussian Blue. Sam Weller addresses his father as Vell, my Prooshan Blue.