Louis' Mixed Drinks with Hints for the Care & Serving of Wines by Louis Muckensturm (1906, p.70)

3 unitsegg — Eggsbase
1 wine-glassJamaica rum base
1 quartmilk — Fresh warm milkdilution
2 tablespoonfulssugar — Powdered sugar or maple syrupsweetener
  1. Beat the eggs well, add sugar or maple syrup and the rum, then slowly add the warm milk, stir in a punch-bowl, top with nutmeg, and serve in cups.

Garnish: Nutmeg

The book says this is sufficient for four to six people.