Green’s Dictionary of Slang

(drugs) synthetic morphine.

1959		W. Burroughs Naked Lunch (1968) 240: Maybe they’re putting some synthetic shit in it . . . Dollies or something.
1964		Larner & Tefferteller Addict in the Street (1966) 58: I had a doctor right up here on 14th Street – he was giving out dollies and goofballs to everyone.
1974		P. Gent North Dallas Forty 18: We’ll get some dollies.
1989		(con. 1940s) Courtwright & Des Jarlais Addicts Who Survived 148: He gave me a handful of dollies when he came back, right after the war, ’45.