Original sentence: The Spanish dollar as a unit of account was introduced in 1839 in order to facilitate the introduction of British sterling silver coinage.The explanation for this lies in the fact that the dollar unit of account acted as a convenient intermediatory conversion unit between sterling and the outgoing Guilder unit.They were formally ceded to the United Kingdom in 1815 and united into the colony of British Guiana in 1831
Edited sentence: In 1839, the Spanish dollar as a unit of account was introduced in order to facilitate the introduction of British sterling silver coinage.The rationale behind this lies in the fact that the dollar unit of account acted as a convenient intermediatory conversion unit between sterling and the outgoing Guilder unit.These territories were formally ceded to the United Kingdom in 1815 and united into the colony of British Guiana in 1831