a law can fall into desuetude
Dazu ein Beispiel aus Nigel Cawthornes Buch: Eine Regel aus dem Jahre 1539 verbietet es den Mitgliedern des Unterhauses, the cloth of estate* zu berühren. Dieser Baldachin oder Überwurf wurde aber am 16 Oktober 1834 beim großen Brand zerstört und nie ersetzt.
* "a cloth spread over a throne or other seat of dignity" — in other words, a canopy or baldachin, which is further denned in the Oxford Dictionary as ( 1 ) A rich embroidered stuff, originally woven with woof of silk and warp of gold thread; rich brocade.
Edward Frank, Laws and flaws: lapses of the legislators, 1956
Whatever the cloth of estate was, Randolph Churchill maintained in the Daily Telegraph of 1 December 1952, the law no longer applied because it would have been destroyed in 1834 when the old Palace of Westminster burnt down. The distinguished lawyer Edward F. Iwi took issue with this. He maintained that the original canopy mentioned in the 1539 Act would have worn out long before 1834 and there would have been several cloths of estate in the meantime. That did not mean the law was invalid.
He pointed to the Statute Law Revision Act of 1948, which amended section two of the House of Lords Precedence Act of 1539, but left section one, which mentions the cloth of estate, alone. If the cloth of estate no longer existed, he argued, surely Parliament would have repealed it. 'The failure to repeal section one shows that the legislature believed that the existing canopy over the throne is the cloth of estate,' he reasoned. He also pointed to the Standing Orders of the House of Lords, adopted on 27 March 1621, which say: 'When the House is sitting, every Lord is to make obeisance to the cloth of estate on entering the House.' These Standing Orders are still in force and lords are still required to bow towards the throne upon entering the chamber. But what they are bowing to is the cloth of estate as there is no obligation to bow to the throne.
[...] It ought to be pointed out that the current throne in the House of Lords has a carved wooden canopy.
Nigel Cawthorne, The Ludicrous Laws of Old London