Three waters or five waters??

Sugar from the West Indies had become a major Glasgow
import before the middle of the 18th Century,the Union 
of 1707 having opened up the West Indies sugar
imports to the City just as it had with Tobacco from
Virginia.

Rum(made from sugar)thus became the characteristic 
Glasgow spirit of that Century.Bankers,merchants,
doctors and lawyers regularly took a '' merdian'' or
noon drink in a tavern or coffee house,often meeting
their clients or customers and sharing a glass of rum
and hot-water (''three-waters'' rum or ''five-waters 
rum according to strength).Sometimes they would
drink claret,and the less prosperous would indulge 
in a chopine(half-pint)of two- penny ale.But rum 
was by far the greater Glasgow Drink