Spiced Rum

Cocktail Boothby's American Bar-Tender by Wm. T. Boothby (1891, p.31) — Hot

1. Dissolve the sugar in a hot-water glass three-quarters full of boiling water.
2. Add Jamaica rum to nearly fill, add assorted spices, and serve.

This is a useful hot-service checkpoint because Boothby keeps the rum-and-spice line distinct from the buttered and molasses branches.

The optional butter note matters as service logic even though it does not define the base drink.

The Complete Buffet Manual or How to Mix Fancy Drinks by J. E. Sheridan (1901, p.63) — Hot

1. Combine the sugar, spices, butter, and Jamaica rum in a whisky glass.
2. Fill with hot water, mix well, and serve.

This preserves the spiced hot-rum branch as distinct from the plainer buttered version.

The spice-and-butter combination is the main structural distinction from plain Hot Rum.

The Artistry of Mixing Drinks by Frank Meier (1936, p.67)

1. Dissolve sugar in a little boiling water in a heated tumbler, add allspice, rum, and butter, fill with boiling water, stir, and serve.

Ice: Ice