Green’s Dictionary of Slang

titillation, sexual provocativeness; in anecdotes, jokes etc, smuttiness.

1859		Wkly Varieties (Boston, MA) 3 Sept. 5/4: Con. Why is the present number of the ‘Varieties’ like a useful article in the cook room? Ans. Because it is all spice.
1878		‘’Arry at the Play’ in Punch 2 Nov. in P. Marks (2006) 39: But now the Stage licks arf the ’Alls, mate, for side-splitters, spice, and bare pink.
1890		‘’Arry on the ’Oliday Season’ in Punch 16 Aug. 75/1: Chic, spice, azure pictures, rum crimes, / Is all very good biz in their way.
1902		Bulletin (Sydney) 26 Jul. 12/3: Margaret Shepherd, the alleged-nun-lecturer, was, in her t’other night’s Sydney lecture ‘to men only,’ a big disappointment to those who expected ‘spice,’ for nothing was said that could ‘bring the blush,’ &c.