Complex sentence: In 1799 the Pneumatic Institution was established at Dowry Square, Hotwells, Bristol, its first superintendent being Humphry Davy, who investigated the properties of nitrous oxide in its laboratory.
Split into simpler sentences: In 1799 the Pneumatic Institution was established at Dowry Square, Hotwells. Its first superintendent wasHumphry Davy, who investigated the properties of nitrous oxide in its laboratory.