Put 2 ounces lump sugar in saucepan with as much water as it will just absorb. Boil to a clear syrup, and then simmer very gently, stirring all the time, until it is a very dark brown, almost black. It must not burn or the flavour will be spoilt. Then add a pint of water, boil for a few minutes. Put into a tightly-corked bottle and use as required.