In 1763 he accompanied the English troops on field service to Madura. There he won the hearts of the officers and the men by his ministrations to the sick and wounded. On his return from Madura he proposed to build a suitable place of worship for the garrison in the fort. His proposal was received favourably and money flowed in. Colonel Wood, who was commanding, assisted, and Schwartz himself contributed a considerable sum.
While he worked among the Europeans he did not forget the cause of the natives whose language he had learned. They, too, felt the spell of his personal influence, which was so strong that the Government appealed to him to help them in their difficulty with Haider. He was entrusted with a political mission to Seringapatam, which he undertook from a sense of duty, although it was much against his will to enter into politics. He hoped that through his mediation peace might be restored to the country. He returned from Seringapatam and became, at the request of the Rajah of Tanjore, tutor to Serfogee, his adopted son.
The natives of Trichinopoly as well as of Tanjore worshipped him, and ascribed to him the qualities they attribute to their own heathen ascetics. Stories of him remain to this day which indicate his vigorous and practical mind.
On one occasion when he was in Ramnad he met a convert who had been behaving badly and had brought disgrace upon his name as a Christian. Schwartz administered a sharp reproof. He concluded with the words:
'Will you have my punishment or the Rajah's?'
'I will have yours, sir,' replied the repentant sinner.
'Then kneel down.'
The man knelt obedient to his word, and Schwartz administered a severe caning.
