MR. THOMPSON said that before proceeding to the subject decided upon for that evening's discussion, he must, in justice to himself and his cause, offer a remark or two. He had on the previous evening been struck with surprise at the extraordinary injustice of charging him (Mr. T.) with quoting unfairly from the letter of Mr. Breckinridge in the New-York Evangelist. It must have been obvious to all, that in the first instance, he quoted from memory, but all would recollect with the avowed wish of avoiding misrepresentation, he had gone to his table--produced the letter, and read the passage entire without the omission or interpolation of a letter or a comma. He, therefore, emphatically denied the charge of garbling. Mr. Breckinridge did himself, immediately afterwards, read the passage, and read it precisely as he (Mr. Thompson) had read it. The imputation, therefore, was equally unfounded and unfair. He (Mr. T.) was thankful that his argument needed not such help. It would be as absurd as it would be wicked for him to attempt to support his cause by any garbled statement. He begged also that it might be distinctly understood that he had by no means exhausted the evidence in his possession on the subject of Colonization. He could adduce a thousand times as much as that which had been already brought forward. He had much to say of the colony at Liberia; the means taken to establish it, the nature of the climate, the character of the emigrants, the mortality amongst the settlers, how much it had done towards the suppression of the slave trade, &c. In fact, he was prepared with overwhelming evidence upon every branch of the subject, and was willing to return to it at any moment, confident that the arguments he could produce, and the facts by which he could support them, would, in the estimation of the public, destroy forever the claim of the Colonization Society to be considered a pure, peaceful, or benevolent institution. I now, (said Mr. T.) come to the topic immediately before us.