Perhaps the most familiar liquid-solid solution is dental amalgam, used to fill teeth when there is a cavity. Approximately 50% of the amalgam material is liquid mercury to which a powdered alloy of silver, tin, and copper is added.
The 'northern part of the subcontinent' consist of northwest lands which have access to Indus river and the northeastern regions have access to Ganga river.
As the northern parts consist mainly rows of hills, water formed from here is pure and sources of fresh water. These rivers have been the source of water for farmers in the northern region to cultivate crops.