Every bill of sale shall be duly attested, and shall be registered under the principal Act within seven clear days after the execution thereof, or if it is executed in any place out of Ireland then within seven clear days after the time at which it would in the ordinary course of post arrive in Ireland if posted immediately after the execution thereof; and shall truly set forth the consideration for which it was given; otherwise such bill of sale shall be void in respect of the personal chattels comprised therein.