Whenever a vehicle delivers to an individual purchaser a commodity in bulk and the commodity is sold in terms of weight units, the delivery shall be accompanied by duplicate delivery tickets on which, in ink or other indelible substance, there shall be clearly stated:
(1) The name and address of the vendor;
(2) The name and address of the purchaser, and
(3) The net weight of the delivery and the gross and tare weights from which the net weight is computed, each expressed in pounds.
One of these tickets shall be retained by the vendor and the other shall be delivered to the purchaser at the time of delivery of the commodity or shall be left at a safe place at the place of delivery or shall be surrendered, on demand, to the Secretary of Agriculture, or an inspector, who, if the inspector desires to retain it as evidence, shall issue a weight slip in lieu thereof for delivery to the purchaser; provided, that if the purchaser carries away the purchase, the vendor shall be required only to give to the purchaser at the time of sale a delivery ticket stating the number of pounds of commodity delivered.