"Oil of lavender 2dr., essence of lemon 4dr., essence of bergamot 1 oz. : mix [1dr. with 8 oz of fine Scotch snuff constitutes Queen’s Snuff]"
Henry Beasley - The Druggist’s General Receipt Book.... 1850
Might be interesting for some readers here to manufacture home-made Queen’s using the recipe quoted by Beasley to see how it compares to the version by Wilsons of Sharrow. Queen’s is now sold as Queen’s Extra Strong (same as Tom Buck) so 1 drop:4 oz seems reasonable. What constitutes "fine Scotch snuff" is debatable, but anyway, there is the recipe.