The Council may pay to the members thereof and to the members of the Assistant Nurses Committee and to the members of the Mental Nurses Committee sums (to be calculated in accordance with directions to be given by the Secretary of State) in respect of any loss of earnings they would otherwise have made or any additional expenses (including travelling and subsistence expenses) to which they would not otherwise have been subject, being loss or expenses necessarily suffered or incurred by them for the purpose of enabling them to perform duties as members of the Council, or either of the said Committees, as the case may be.