Complex sentence: The following year Hopkin Morris was appointed as a Metropolitan Police magistrate, a salaried post which vacated his seat because the post was an'office of profit under the Crown' and incompatible with membership of the House of Commons.
Split into simpler sentences: The following year Hopkin Morris was appointed as a Metropolitan Police magistrate. He gave up his seat in consequence: the post was an'office of profit under the Crown' and incompatible with membership of the House of Commons.