Hot Scotch

The Complete Bartender by Albert Barnes (1884, p.6)

1. Use a small bar glass.
2. Add the Scotch whiskey, fill the balance of the glass with boiling water, and drop in a lump of sugar and some thin yellow shavings of lemon peel.
3. Stir well and serve.

Garnish: Lemon peel

New Guide for the Hotel Bar Restaurant by Bacchus (1885, p.6)

1. Use a small bar glass.
2. Add the Scotch whiskey, fill the balance with boiling water, and drop in a lump of sugar and some thin yellow shavings of lemon peel.
3. Stir well and serve.

Garnish: Lemon peel

The Cocktail Book a Sideboard Manual for Gentlemen (1901, p.53)

1. Fill a hot water glass two-thirds full with boiling water and dissolve the sugar.
2. Add the Scotch whisky and lemon peel and serve with a spoon.

Garnish: Lemon peel.

This is a straightforward private-house witness for hot Scotch before later hotel-bar codification.

The drink is intentionally plain: sweetener, hot dilution, spirit, peel, spoon.

Jack's Manual by J. A. Grohusko (1910, p.56)

1. Build the sugar, bitters, boiling water, and Scotch whiskey in a glass.
2. Add a piece of lemon peel and a few cloves, then serve.

Garnish: Lemon peel and cloves

Ice: None

Julian's Recipes by Julian Anderson (1919, p.14)

1. Put the sugar and Scotch whiskey in a hot water glass, twist lemon peel over the glass, and drop it in.
2. Fill with boiling water, grate nutmeg on top, and serve.

Garnish: Nutmeg and lemon peel

The Old Waldorf-Astoria Bar Book by Albert Stevens Crockett (1935, p.88)

1. Build in a hot glass and serve.