law: 35. Liability of guardians, trustees, etc.
  Where the business in respect of which tax is payable
  under this Act is carried on by, or is in the charge of any guardian, trustee or agent of a minor or other incapacitated person on his behalf and for the benefit of such minor or other incapacitated person, the tax (including any penalty) shall be levied upon and recoverable from such guardian, trustee or agent, as the case may be, in like manner and to the same extent as it would be assessed upon and recoverable from any such minor or other incapacitated person, if he were of full age and of sound mind and if he were conducting the business himself, and all the provisions of this Act shall, so far as may be, apply accordingly.