The son early evinced a passion for the acquisition of knowledge, and in addition to some familiarity with Latin, soon became proficient in French, without the assistance of a master. To do this, however, he studied as much as fifteen or sixteen hours a day, hardly allowing himself time for his meals. The peculiar orthography of his Christian name as rendered by himself, “Mathew,” and not “Matthew,” was the result of a philological discussion with one of his brothers, when quite a young man, and his then arriving at a belief that from its derivation this was the correct mode of spelling it. When about fifteen years of age it became necessary for Mathew to choose a trade. He was decidedly in favor of that of printer and bookseller, which were then generally united. His father had a strong aversion to the trade, and refused to look out a master for him, which he did for himself, and he was accordingly apprenticed to a printer and bookseller of the name of McDonnel. A lameness which took place owing to the carelessness of his nurse when he was about a year old, and which continued throughout life, was a constant drawback to him, and interfered greatly with him in his career. His first essay as a writer was when he was about seventeen years old, and was on the subject of dueling, which he condemned with great severity—the occasion being the attempt of a bookseller in Dublin to bring about a duel between an apprentice of his own and one of McDonnel’s. As will be seen, however, after he came to the United States, Mr. Carey was himself a principal, and was wounded in a duel. His next attempt at authorship was one which involved most serious consequences to himself, and drove him into exile. Having directed his attention to the oppressions under which the Irish Catholics stood, and having read every book and pamphlet on the subject which he could procure, and with his mind filled with their sufferings, and his indignation aroused, he, in 1779, wrote a pamphlet entitled _The Urgent Necessity of an Immediate Repeal of the whole Penal Code against the Roman Catholics, Candidly Considered; to which is added an inquiry into the prejudices against them; being an appeal to the Roman Catholics of Ireland, exciting them to a just sense of their civil and religious rights as citizens of a free nation_. When nearly ready it was advertised for publication in a few days, with the title page and its mottoes, and the attention of the public was called to it by an address, couched in very strong language, and wherein reference was made to the fact that “America by a desperate effort has nearly emancipated herself from slavery.” It excited considerable alarm. Parliament was then in session, and the advertisement was brought before both houses. The publication was denounced by an association of Roman Catholics, which, as Mr. Carey has asserted, “partook of the general depression and servile spirit, which a long course of oppression uniformly produces.”