evidence: (2) When the Sinhala language is made a medium of instruction in the University of Ceylon, the Tamil language shall, in accordance with the provisions of the Ceylon University Ordinance and of the Statutes, Acts and Regulations made thereunder, be made a medium of instruction in such University for students who, prior to their admission to such University, have been educated through the medium of the Tamil language. [...] 4. Correspondence between persons, other than officials in their official capacity, educated through the medium of the Tamil language and any official in his official capacity or between any local authority in the Northern or Eastern Province and any official in his official capacity may, as prescribed, be in the Tamil language. 5. In the Northern and Eastern Provinces the Tamil language may be used for prescribed administrative purposes, in addition to the purposes for which that language may be used in accordance with the other provisions of this Act, without prejudice to the use of the official language of Ceylon in respect of those prescribed administrative purposes.