Together with his business partner and brother-in-law, William Gill, Thomas was active in several London hospital charities which provided for the poor of London. He was a governor of St Thomas’s Hospital but the hospital he was most involved in was the City of London Lying-in Hospital, one of the first maternity hospitals in London.
Thomas first became involved with ‘this humane and useful institution’, which provided maternity services for the wives of poor tradesmen, in the 1770s when he joined the board in return for a donation of 10 guineas. He would attend the Sunday baptisms of babies born in the hospital, make donations and attend meetings where the governors would hire staff, sign off on bills and deal with admittance applications: there were always more expectant mothers than beds available.
Charity in the eighteenth century was often moralistic and the hospital was strictly for married women only, single women would not be admitted until 1912. Each governor had the right to nominate patients but all the patients had to prove they were married, were deserving of charity and agree to their new-born being baptised in the hospital chapel.