The Buffet Blue Book by John H. Considine (1912, p.36)

1 piecelemon peel acid
1 wine glassScotch whisky — Scotch whiskeybase
1 lumpsugar base
hot water — Enough to dissolve sugar and fill the glass.dilution
nutmeg — Grate on top.other
  1. Prepare the drink in the same manner as Hot Whiskey Sling, substituting Scotch 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.

The Up-to-Date Bartender's Guide by Harry Montague (1913, p.46)

1 slicelemon peel acid
1 jiggerScotch whisky — Scotch whiskeybase
1 lumpsugar — Dissolved in the glass.base
hot water — Fill up.dilution
nutmeg — Sprinkled on top.other
  1. Substitute Scotch for Irish whiskey and proceed as for Hot Irish Whiskey.
  2. Serve hot with lemon peel and nutmeg.

Garnish: Lemon peel and nutmeg

Source is explicitly substitution-based.

See also: Hot Irish Whiskey, Hot Scotch Whiskey Sling

Source says to substitute Scotch for Irish whiskey and proceed as for Hot Irish Whiskey.