The Complete Buffet Manual or How to Mix Fancy Drinks by J. E. Sheridan (1901, p.56)

1.5 dasheslemon juice — Sheridan gives 1 or 2 dashes.acid
1 wine glassIrish whiskey — Irish whiskybase
3 teaspoonfulssugar — powdered sugarbase
water — hot waterdilution
1 slicelemon slice garnish
  1. Combine the sugar, lemon juice, and Irish whisky in a large bar glass.
  2. Fill with hot water, stir well, place a slice of lemon on top, grate a little nutmeg, and serve.

Garnish: Lemon slice and grated nutmeg.

This is a useful hot-whiskey checkpoint because Sheridan keeps the compact bar-glass service explicit.

The lemon slice and nutmeg are integral finishing steps, not optional decoration.

Jack's Manual by J. A. Grohusko (1910, p.57)

0.5 lemonlemon juice — Juice of half a lemon.acid
1 portionIrish whiskey — Source gives 100% Irish whiskey.base
2 lumpssugar base
hot water — Dissolve in a little hot water, then fill glass with hot water.dilution
1 slicelemon slice — Place slice of lemon on top.garnish
nutmeg — Grate nutmeg and serve.other
  1. Dissolve the sugar and lemon juice in a little hot water and add the Irish whiskey.
  2. Fill with hot water, stir well, place a slice of lemon on top, grate nutmeg, and serve.

Garnish: Lemon slice and grated nutmeg

Ice: None

The Buffet Blue Book by John H. Considine (1912, p.37)

4 dasheslemon juice acid
1 piecelemon peel acid
1 jiggerIrish whiskey — Substituted for whiskey.base
2 lumpssugar base
hot water — Enough to dissolve the sugar and fill the glass.dilution
nutmeg — Grate on top.other
  1. Prepare the drink in the same manner as Hot Whiskey Punch, substituting Irish whiskey for whiskey.
  2. Stir with a spoon, grate nutmeg on top, and serve.

Garnish: Lemon peel and grated nutmeg

Ice: None

This entry is explicitly substitution-based in the source.

Bartenders' Manual by Bartenders Association of America (1913, p.30)

1 slicelemon — Lemon sliceacid
1.5 dashlemon juice — Lemon juiceacid
1 wineglassIrish whisky base
1.5 lumpsugar — Sugarbase
hot water — Hot waterdilution
  1. Stir well, place a slice of lemon on top, and grate nutmeg.

Garnish: Lemon slice and nutmeg

The Up-to-Date Bartender's Guide by Harry Montague (1913, p.33)

1 piecelemon peel — Twisted over and dropped in.acid
1 jiggerIrish whiskey base
1 lumpsugar — Dissolved with a little hot water.base
hot water — Fill up.dilution
nutmeg — Sprinkled on top.other
  1. Dissolve the sugar with a little hot water in a hot whiskey punch glass.
  2. Add the Irish whiskey and fill up with hot water.
  3. Twist a piece of lemon peel over the drink and drop it in, stir, sprinkle with nutmeg, and serve.

Garnish: Lemon peel and nutmeg

Home Brewed Wines and Beers and Bartenders' Guide by Johnson Smith & Company (1918) — 1918 Home Brewed, How to Mix Drinks opening section

1 slicelemon acid
2 dashLemon juice (fresh) — lemon juiceacid
3 teaspoonfulpowdered sugar base
1 wine-glassWhiskey — Irish whiskeybase
tophot water dilution
gratednutmeg other
  1. Fill with hot water, stir well, place lemon on top, grate nutmeg, and serve.

Garnish: Lemon slice and grated nutmeg

Ice: None

See also: Hot Rum Punch, Hot Whiskey Punch

Source says to prepare it the same as the above, using Irish whiskey instead.