In the eighteenth century, opinion was split on the effects of green tea: on one side of the debate, people regarded it as highly beneficial; it was particularly popular with young women. One other side, there was an idea that consumption, or TB, was caused by excessive amounts of the drink. Dr Beddoes subscribed to the latter. In 1799, he decided to carry out an experiment to prove his concerns, having two large ponds dug out in the garden of the Institute – one to be filled with fresh water, the other with green tea. He also needed a large amount of frogs, which he ordered from Shropshire, to arrive in Bristol by ship. Unfortunately, when unloading the frogs, the rope on the crane broke, thus releasing the cask of reportedly 10,000 frogs onto the Quay. A large number hopped into the Frome, much to the astonishment and dismay of local residents. The word spread that Beddoes, a known radical, was harbouring French Jacobins in his basement and that the casket of frogs had been ordered as food. As a result, an angry mob started marching towards Rodney Place, with the expressed desire to set it on fire, which was interceded and calmed by a fellow doctor.
And what became of the frogs? Some were gathered and used in Beddoes’ experiment. Those that escaped, unfortunately, didn’t last long: the increasing use of the Frome as an open sewer combined with the loss of the scouring action of the tides meant that it had become highly polluted. In 1825 it was again diverted, with locks at Stone House, channelling the main flow through Mylne's Culvert to the tidal Avon at New Cut, to the east of what is now Gaol Ferry Bridge.