No unmixed whiskey, unmixed rum or unmixed gin shall be sold or offered for sale at retail for consumption on the premises except in a container having a minimum capacity of at least one fluid ounce and which contains at the time of sale at least one fluid ounce of the beverage being sold. No person licensed to sell alcoholic liquor at retail for consumption on the premises shall use in such sales or possess on the premises any glass or other container so constructed as to be deceptive in appearance or to mislead the consumer as to its true capacity.
('73 Code, § 34.21) Penalty, see § 10.99