Rum Shrub

Does anyone know about the history of Rum Shrub? Specifically where the name comes from, and what the recipes that are historically correct for the 19th Century are?

I have seen Rum, and Brandy, Shrub recipes which contain lemon, lime, orange juice or a mixture of lemon and orange juice. Which would have been the most prevalent in the 1800s?

Cheers!

George

I have a book, 'Drinking with Dickens', written by Cedric Dickens, Charles Dickens' great-grandson. He says Dickens called the drink "srub". He gives some historical background on much of the types of drink mentioned in Dickens books, as well as recipes. However, there was nothing specifically about the shrub, other than a couple of recipes.
He mentioned that rum (it would have been Jamaican) was usually a winter drink. I'd guess that shrub was a way to preserve orange and lemon, which were seasonal, to have in a winter drink. I ran across a passage in another old book in which a character explains that he drinks hot "rum-srub" because it "opens up the passages".
The name, "shrub" or "srub", seems to come from Arabic, for drink, and is related to sirup and sherbet. (http://dict.die.net/shrub)
Here's the two old recipes Cedric has in the book:

Shrub I
1/2 gallon rum
3/4 pint orange juice
1/2 pint lemon juice
peel of two lemons
2 lbs sugar loaf
Slice lemon peel very thinly and put it with the fruit juice and spirit in a large covered jar. Let it stand for two days, then pour over it the water in which the sugar has been dissolved. Take out the lemon peel and leave for twelve days before using.

Shrub II
1/2 lb strained Seville orange juice
2 lbs crystal sugar
3 pints rum or brandy
Dissolve sugar in cold orange juice and blend with spirit. Strain through a jelly bag. Bottle and cork.