What does “do.” mean in old recipes

cocktailslanguage

I'm reading through a book of cocktails from 1865 and I often seen the measurement for a given ingredient listed as "do.". What does this mean?

Examples:

40 1/2 ounces of roast and ground cocoa.
6 2/3 do. ground cardamom seeds.
6 2/3 do. ground Ceylon cinnamon.
7 pints of alcohol, 95 per cent.
20 do. water.

Or:

2 gallons of ground malt.
6 do. water, at 142° (degrees) heat.

Or, most bafflingly:

1 pound = 16 ounces
1/2 do. = 8 do.
1/4 do. = 4 do.

Best Answer

I suspect it means "ditto (the above line)": http://en.wikipedia.org/wiki/Ditto_mark seems to indicate that "do." was an old way of abbreviating before the ditto mark (") became widespread.