M'Gavin found time, amidst his numerous mercantile avocations, to write a
number of religious tracts and stories, for the improvement of the poorer and
junior classes of society. Though these productions are of a class which do not
usually attain a high place in literature, no reader, however indifferent to the
subjects, or of however highly cultivated intellect, could peruse them, without
remarking the extraordinary conciseness of style and moral force by which they
are characterized. The most distinguished of all Mr M'Gavin's writings is his
" Protestant," a series of papers, designed to expose the errors of the church of
Rome, commenced in 1818, and finished in 1822. In the general decline of
religious controversial writing, the celebrity acquired by this work, is a strong
testimony to the powers of the author. In its collected form, in four volumes
octavo, it went through no fewer than seven editions in the first ten years.
According, to Mr Greville Ewing, in a funeral sermon upon Mr M'Gavin,
"the commencement of the work was casual, and the whole executed with hasty
preparation. While engaged in a mercantile business of his own, he had at
that time the winding up of an old concern of his partner, the heavy charge of
another concern, which in the end proved a severe loss to him, besides other
business matters, as factorships, references, as sole arbiter, in cases both from
private parties and from the Court of Session, which he decided in a manner
satisfactory to all concerned; and many other things were devolved on him,
which none but a man of clear judgment, and unusually industrious habits, could
have undertaken. A work which, otherwise, would have been extremely irksome, was rendered pleasant by the continued and increasing favour with which it was received by the public in general, and by the approbation of distinguished
individuals in each of the three kingdoms. One of the most eminent bishops of the church of England offered to give him holy orders. That, however, which was most gratifying to the author, was the interest which he was honoured to
excite in the public mind, with regard to the subject of popery. I make no attempt to give a particular account of the contents of this work. It is impossible, they are so extensive: it is unnecessary, they are so generally known. It is
matter of notoriety, that Mr M'Gavin was prosecuted for certain articles in the Protestant, and had a verdict against him, imposing on him a fine of £100, which, with expenses, amounted to above £1200. Into the merits of these things I shall not enter, further than to state, in round numbers, that £800 of the £1200, was raised by public subscription, and that the whole, it was believed, would have been more than paid, had not each subscriber been limited to a certain sum. As the case had been so arranged, Mr M'Gavin was obliged, in the mean time, to pay the balance out of his own pocket ; of which, great as
the amount was, I never heard him complain. The publishers afterwards very handsomely came forward to reimburse the author, which, from the sale of the work, they were enabled to do without loss to themselves, though he had no claim upon them."
Mr M'Gavin, in 1827, superintended a new and improved edition of "The Scots Worthies," a work commemorating the lives of the most eminent Scottish clergy of the sixteenth and seventeenth centuries, and originally written by an unlettered individual named John Howie, of Lochgoin. The book was greatly improved by the notes of Mr M'Gavin. He soon after published a refutation of the peculiar views of Mr Cobbett in his History of the Reformation; and a similar exposure of the principles of Mr Robert Owen. Being a decided enemy to the connexion of the church and state, he was induced to embody his sentiments on that subject in a pamphlet, entitled " Church Establishments considered; in a Series of Letters to a Covenanter." Not long before his death, Mr M'Gavin superintended a new and improved edition of Knox's History of
