(9)When put as under Sub-rule (8) and as soon as the surface of the undenatured spirit has come to rest, it should be gauged and proved by the officer-in-charge, and denaturants from the vessels referred to in Sub-rules (3) and (4), as necessary, added to it in the proportion as prescribed in the formulae of the Standing Technical Committee referred to in Sub-rule (2) of Rule 51 and as may be specified in the licence according to the said formulae, in the presence of the officer-in-charge and of the licensee or his agent, and the admixture thoroughly stirred in their presence with a proper stirring implement.
