.Every medical certificate referred to in sub-section (6) of section 20 shall contain a statement,

(a) that each of the medical practitioners referred to in that sub-section has independently examined the alleged mentally ill person and has formed his opinion on the basis of his own observations and from the particulars communicated to him; and

(b) that in the opinion of each such medical practitioner the alleged mentally ill person is suffering from mental disorder of such a nature and degree as to warrant the detention of such person in a psychiatric hospital or psychiatric nursing home and that such detention is necessary in the interests of the health and personal safety of that person or for the protection of others.