Bartenders' Manual by Bartenders Association of America (1913, p.21)

2 dashgum syrup — Gum syrupbase
0.33 partOld Tom gin — Equal one-third proportion.base
0.33 partScotch whisky — Equal one-third proportion.base
2 dashorange bitters — Orange bittersbitter
1 pieceCherry or olive — Cherry or olivegarnish
0.33 partItalian vermouth — Equal one-third proportion.modifier
  1. Mix and serve with either a cherry or an olive.

Garnish: Cherry or olive