Ammonia may be made by heating an intimate mixture of sal-ammoniac and slaked lime and passing the gas evolved into water until the latter is saturated, but the method would be very expensive. Ammonia is now made in large quantities by distilling gas-liquor, liquor from coke ovens, or washing waters used in scrubbing the gas from blast furnaces, with lime; ammonia can be bought so cheaply that it does not pay to make a small quantity.