6. Validation of certain acts and indemnity in respect thereof.- All acts of executive authority, proceedings and sentences which have been done, taken or passed with respect to, or on account of, any inflammable substance since the 1st day of April, 1937, and before the commencement of this Act by any officer of Government or by any person acting under his authority or otherwise in pursuance of an order of the Government in the belief or purported belief that the acts, proceedings or sentences were being done, taken or passed under the Petroleum Act shall be as valid and operative as if they had been done, taken or passed in accordance with law; and no suit or other legal proceeding shall be maintained or continued against any person whatever on the ground that any such acts, proceedings or sentences were not done, taken or passed in accordance with law. | 