Complex sentence: In 1823 he partnered with William Henry Perrins, opening a drug store in Worcester, and in 1837 they began selling the Lea & Perrins brand of Worcestershire sauce.
Split into simpler sentences: In 1823 he partnered with William Henry Perrins, opening a drug store in Worcester. In 1837 began selling the Lea & Perrins brand of Worcestershire sauce.