Pint (Ontario), about 1 litre versus 0.5 litres. After four of the British provinces united in the Canadian Confederation in 1867, Canada legally adopted the British imperial system of measure in 1873, making Canadian liquid units incompatible with American ones from that year forward. In 1873, the French Canadian "pinte" was defined as being one imperial quart or two imperial pints, while the imperial pint was legally called a "chopine" in French Canada. Canadian imperial units of liquid measure remain incompatible with American traditional units to this day, and although the Canadian pint, quart, and gallon are still legal units of
Pint measure in Canada, they are still 20% larger than the American ones. In the British and Irish metrication processes, the pint was replaced by metric units as the legally defined primary unit of measure for trading by volume or capacity, except for the sale of draught beer and cider, and milk in returnable containers. The pint can still be used in those countries as a supplementary unit in all circumstances. Legislation in the UK mandates the use of the pint as a measure for draught beer and cider (in pubs for instance). For milk, if returnable containers are used, the