asked the Minister of Fuel and Power what research has been made by his Department to ascertain the maximum amount of by-products that can be obtained from a ton of coal, giving the name of each by-product; and what would be their value in the British market.

The increased efficiency of the various coal treatment processes is a main objective of the research and development programmes of the industries and others concerned. The main by-products are crude tar, ammoniacal liquor, spent oxide and crude benzole but no reliable estimate of their total value can be made.