Beverage called "flip"?

Barnaby Rudge, by Charles Dickens

What’s “flip”?

Flip.

According to Cassell’s Dictionary of Slang flip, in the context of your quote, means a mixture of beer and spirit sweetened with sugar and heated with a hot iron.

There is also a drink called egg-flip which is a sort of egg-nog or Advocaat

I used to run with a guy who was a bouncer at a breast bar. The dancers would get fifty cents for every drink a customer bought for them. Naturally, they had lots of drinks bought for them. To avoid getting blind drunk, the girls would order a flip, which, in that bar, was a Coke. The customer, of course, was getting messed over every which way. He dreams he’s going to take the dancer home, and he won’t. He thinks he’s buying an overpriced mixed drink for her, and he’s buying an extremely overpriced Coke. He thinks she’s flirting with him because she wants his body, but flirting with him is her job.

I believe that’s just a flip. A flip should have egg white and cream in it. When prepared properly, it is quite nasty. External-use-only nasty.

That reminds me of a medieval drink called a posset, made with wine and eggs, often consumed for breakfast. A friend of mine in the SCA knows how to make them; I’ve never succeeded.

A recipe for egg-flip :-

EGG FLIP
Ingredients
4 eggs
4tsp caster sugar
4tbs brandy
1pt milk
whole nutmeg

Method
seperate the eggs then beat the sugar and the egg yolks together. Add the brandy and stir. Heat the milk and pour it over the egg and brandy mix. Whisk the egg whites until stiff and fold into the milk, egg and brandy.

bottle this and keep in fridge for about a week
add lemonade to about an eggcupful in a half pint glass and youve got a snowball