Green’s Dictionary of Slang

one shilling (5p).

1753		J. Poulter Discoveries (1774) 43: Mejoge or Hogg; a Shilling.
1786		Whole Art of Thieving [as cit. 1753].
1886		W. Newton Secrets of Tramp Life Revealed 9: Deaner or Midget ... One Shilling.
1891		F.W. Carew Autobiog. of a Gipsey 418: When Griffin seen the plate turn hup agen like a snide midgic, his face were a picter.
1891		Birmingham Dly Post 31 Mar. 3/4: I append a few cant words and expressions for those who take an interest in the subject [...] midjic (shilling).
1905		Bluefield Daily Tel. (WV) 11 Mar. 4/2: In addition [...] the following [names for money] are given: [...] Mejum.
1955		N. Pulliam I Travelled a Lonely Land (1957) 236/1: midgic – a shilling.