IMPRISONMENT OF O'BRIEN FOR CONTEMPT OF THE BRITISH COMMONS.--CONDUCT OF THE ASSOCIATION.--DEPUTATION FROM THE '82 CLUB.--MR. O'CONNELL RETURNS TO IRELAND.--DISCUSSIONS IN THE COMMITTEE. Before proceeding to detail the circumstances which led to the celebrated secession, it is essential to dispose of an episode in the struggle, which, more than any other, stamped its impress on the acts and feelings of that unfortunate period; I allude to the imprisonment, by the House of Commons, of William Smith O'Brien. There is no act of his life upon which there has been so much acrimonious criticism; none on account of which he has been subjected to so much intemperate misrepresentation. And yet, perhaps, his great career, fruitful in good actions, never furnished a purer or more unselfish example of sound judgment as well as intrepidity and devotion. The history of his incarceration ranges over a great portion of the time which has been already passed, and enters largely into the leading events, hereafter to be related. A clear understanding of the whole--of Mr. O'Brien's influencing motives and his tenacity of principle--would be impossible without a distinct recital of the circumstances out of which his purpose first grew, and which, to the end, controlled his resolution. In the spring of 1845, the committee of the Association passed a vote to the effect that the Parliamentary representatives, who were members of that body, should withdraw from the British Parliament. It was proposed by Mr. Davis and received Mr. O'Connell's entire approval. Though at first sneered at, it had a stunning effect. The supercilious British Commons, who would have answered the just remonstrance of the Irish Repealers with a jeer, shrank from the consequences of legislating for the country in the absence of the men, whose efforts, if present, they would not hesitate to scoff at. The disturbing influence of the resolution became at once perceptible, and the earliest means were taken to bring the question to an issue. Mr. Hume, a parsimonious economist, of niggard principle and grovelling sentiment, undertook the office of coercing the Irish. He gave notice of a motion for a call of the House. This man, a mean utilitarian, had been rejected by the country of his birth and the country of his adoption, and found refuge in an Irish constituency, that returned him without solicitation and without expense. He repaid them and the country by a vulgar jest, and now assumed the responsibility of their public prosecutor.