It should be considered whether the history of this drink should not be integrated by reporting this recipe present in the "Old Waldorf-Astoria Bar Book", 1935, p. 53:

"HEARN'S
Dash of Manhattan Bitters
One-third Whiskey
One-third Italian Vermouth
One-third Absinthe"

There is another historical fact worth remembering today.
On 1495, the first known batch of Scotch whiskey was registered by order of the king to Friar John Cor. Slàinte Mhath!