If a union with the colonies were to take place, those commodities might be taxed, either before they go out of the hands of the manufacturer or grower; or, if this mode of taxation did not suit the circumstances of those persons, they might be deposited in public warehouses, both at the place of manufacture, and at all the different ports of the empire, to which they might afterwards be transported, to remain there, under the joint custody of the owner and the revenue officer, till such time as they should be delivered out, either to the consumer, to the merchant retailer for home consumption, or to the merchant exporter;