Subject to such rules regulating the t ime, place and manner as the State Government may prescribe, such duty shall he levied ratably on the quanti t y of excisable art icle imported, exported, transported, collected or manufactured in or issued from a dist i l lery, brewery or warehouse:
Provided that—
(1) duty may be levied—
(a) on intoxication drugs by an acreage rate levied on the cult ivation of the hemp plant or by a rate charged on the quanti ty collected;
(b) on spiri t or beer manufactured in any dist i l lery established or any dist i l lery or brewery l icensed under this Act —
(i) in accordance with such scale or equivalents calculated on the quanti ty of materials used, or by the degree of at tenuation of the wash or wort , as the case may be, as the State Government may prescribe, or;
( i i) by a rate charged directly on the materials used;
(c) on tan, by a tax on each tree from which the tan is drawn.
(2) Where payment is made upon the issue of an excisable art icle for sale from a warehouse, i t shall be at the rate of duty in force on the date of issue of such art icle from the warehouse,
(3) Where the rate of duty is enhanced or reduced after payment o f duty on issue of excisable art icle from warehouse and the excisable art icle is in stock with a holder of a l icence, the excisable art icle in stock shall be subject to the levy of duty at the rate so enhanced or reduced and the difference in duty shall be payable or refundable, as the case may he, by or to the holder of a l icence, with whom such duty paint excisable art icle is in stock at the material t ime.