25. Staff  26. Class-child ratio  (6) No business other than the election of a President shall be transacted at a meeting of  the National Assembly under subsection (4) of this section or under section 32(6) of this  Constitution and such a meeting or any sitting thereof shall not be regarded as a meeting or sitting  of the Assembly for the purposes of any other provision of this Constitution. (7) At any time when the office of Speaker is vacant or the holder of that office  is unable by  reason of absence or illness to exercise the functions vested in him or her by this section and  section 32(6) of this Constitution, those functions may be exercised by the Deputy Speaker of the  National Assembly or, if there is no Deputy Spea ker or the Deputy Speaker is unable by reason of  absence or illness to exercise those functions, by such member of the Assembly (not being the  President or Vice-President or a Minister or Assistant Minister) as the Assembly may elect for that  purpose. (1) Whenever the President is absent from Botswana or considers it desirable to do so by  reason of illness or any other cause he or she may, by directions in writing, authoriz e-  to discharge such of the functions of the office of President as he or she may specify, and the  Vice-President or other Minister may discharge those functions until his or her authority is revoked  by the President.  (2) If the President is incapable byreason of physical or mental infirmity of discharging the  functions of his or her office and the infirmity is of such a nature that the President is unable to  authorize another person under this section to perform those functions -  shall perform the functions of the office of President. (3) A person performing the functions of the office of President under this section shall not  exercise the power of the President to revoke the appointment of the Vice -President or todissolve  Parliament.  (4) A person performing the functions of the office of President by virtue of subsection (2)  of this section shall cease to perform those functions if he or she is notified by the President that  the President is about to resume those  functions.  (5) For the purposes of this section, a certificate of the Chief Justice that -  Copyright Government of Botswana ( g )  only one ballot shall be taken at any sitting of the Assembly, and the Speaker may  adjourn the meeting at which a second orsubsequent ballot is to be taken for such  number of days (in addition to the days on which and to which the meeting is adjourned),  not being more than two, as he or she thinks fit; ( h )  if there is no candidate duly nominated for the first ballot in accord ance with paragraph  ( b ) or if after the number of ballots permitted under paragraph ( f ) have been taken no  candidate has been declared elected Parliament shall stand dissolved or, in the case of a  Presidential election held in accordance with section 32(6)  of this Constitution, the  foregoing general election shall be void. ( a )  the Vice-President; or  ( b )  during any period when there is no Vice -President or the Vice -President is absent from  Botswana or is, by reason of physical or mental infirmity, unable to perform the functions  of his or her office, some other Minister, ( a )  the Vice-President;or  ( b )  during any period when there is no Vice -President or the Vice -President is absent from  Botswana or the Vice -President is, by reason of physical or mental infirmity, unable to  perform the functions of his or her office, such Minister as the Cabinet  shall appoint,  ( a )  the President is incapable by reason of physical or mental infirmity of discharging the  functions of his or her office and the infirmity is of such a nature tha t the President is  unable to authorize another person under this section to perform the functions of his or  her office; or 36.  Discharge of functions of President during absence, illness, etc. 