In May 1827 he went to London to open the new church of Mr. Irving in Regent Square. This took place on a Friday; the prayer which Mr. Irving offered was forty minutes in length, and it was an hour and a half ere Chalmers was allowed to begin. He preached again on the Sunday, the crowd comprising Mr. Peel, Lord Bexley, Lord Farnham, Lord Mandeville, Mr. Coleridge, and many other notables. At this time he made the acquaintance of Mr. Coleridge, with whom he spent three hours at the Gillmans' house in Highgate; but while he marvelled at the flow of conversation, he said he could only catch occasional glimpses of what he would be at. He had a pleasant talk in the House of Commons with Mr. Peel, who showed a great interest in his views on pauperism, the college commission, and likewise in his sermons, all of which he said he had read. He had some intercourse with Macaulay, and heard Brougham; saw also Sir Francis Burdett (father of Lady Burdett-Coutts), a conspicuous radical politician of the day.
Among home friends, Chalmers remained as simple, unsophisticated, and kindly as before. 'Of all men,' said Mrs. Grant of Laggan at this time, 'he is the most modest, and speaks with undisguised gentleness and liberality of those who differ from him in opinion. Every word he says has the stamp of genius; yet the calmness, ease, and simplicity of his conversation is such, that to ordinary minds he might appear an ordinary man.... He is always powerful, always gentle, and always seemed quite unconscious of his own superiority.' About the same time, Mrs. Grant received a visit from her friend, Sir Walter Scott, and it is interesting to observe the resemblance she saw between the two men. 'His good-nature, good-humour, and simplicity are truly charming. You never once think of his superiority, because it is evident he does not think of it himself. He, too, confirmed the maxim that true genius is ever modest and careless.'
In the autumn of the same year he paid his first visit to Ireland. He had been asked to preach, and crowds as usual thronged to hear him. He was greatly interested in the Giant's Causeway and the surrounding scenery, and seems to have relished the new aspect of character which Ireland furnished. But the place which had the deepest interest for him was Gracehill, a Moravian settlement, where his wife had been educated, and in the cemetery of which was the tomb of her mother. To be on the spot where his mother-in-law, whom he had never seen, departed this life; to converse with the physician that had attended her in her last hours; and to walk through the school-house where his wife had received her education, thrilled his susceptible nature; it was with reluctance that he tore himself from these 'bowers of sacredness.' We can hardly conceive a warmer or more delicate tribute to his wife, or a clearer evidence of his affection for her and her family.
We have already adverted to some of his appearances in the General Assembly, but to these we must now add a remarkable pleading, in 1828, in favour of the repeal of the Test and Corporation Acts. The royal assent had just been given to a bill repealing these Acts, but so vital did the matter appear to Dr. Chalmers, that he proposed that the Assembly should present a humble Address to his Majesty, expressing its satisfaction that it was no longer requisite to take the sacrament as a qualification for civil office. In his speech he compared the old law, viewed as a buttress to the Established Church, to those wooden props which one sometimes sees leaning obliquely against the walls of a house,--creating the impression that when a house needs such props, it is one of the craziest in the street. Yet he was careful to affirm his high regard for an established church in itself, apart from such miserable buttresses. His motion was lost by 123 votes to 77, but in spirit the Assembly agreed with him.