8.In [2]addition to the duty of excise payable . . . . in respect of beer brewed in the United Kingdom, there shall be charged, levied, and paid . . . .
For every thirty-six gallons of worts of a specific gravity of one thousand and fifty-five degrees, the duty of sixpence,
and so in proportion for any difference in quantity or gravity.
[2 Further additional duties imposed, and corresponding drawback provided for by 63 & 64 Vict. c. 7, s. 6.]