of these disaffected persons had hitherto been conducted with such secrecy, that no suspicion of their views was entertained, until the 4th of March in this year, when a violent insurrection broke out at Castle Hill, a settlement between Parramatta and Hawkesbury, and the insurgents expressed their determination to emancipate themselves from their confinement, or to perish in the struggle for liberty.  Information of the extent and alarming appearance of this mutiny having reached the governor, it was deemed necessary, on the following day, to proclaim martial law; and a party of the troops, under the command of Lieutenant-Colonel George Johnston, were directed to pursue the rebels.  After a long march, the military detachment came up with the insurgents, near the Ponds, about half-way between Parramatta and Hawkesbury, and a short parley ensued, when the Colonel found it necessary to fire upon them; and, after killing several of the misguided rebels, and making prisoners of the principals who survived, the remainder made a rapid retreat.  Ten of the leaders of this insurrection, who had been observed as particularly conspicuous and zealous in their endeavours to seduce the rest, were tried on the 8th of March, and capitally convicted.  Three were executed on the same evening at Parramatta, since it was justly concluded, that measures of prompt severity would have a greater effect upon the minds of those who had forsaken their allegiance.  On the following day, two other rebels were executed at Sydney, and three at Castle Hill:  the two remaining criminals were respited, as they were the least corrupted, and had discovered symptoms of sincere remorse for the part which they had taken in the late operations.  On the 9th, martial law was repealed; and from that moment no disturbance has again broken in upon the peace of the settlement of a serious nature, although it would be too much to suppose that the seeds of insubordination and disorder were entirely eradicated by the frustrated event of the first endeavour.  Men of such desperate characters as are to be found in this colony, are not to be intimidated by punishment, nor discouraged by failure from the pursuit of that career of depravity, which is become dear to them from habit; nothing short of death can destroy, in those minds, the affection for vice, and the determination to gratify their ruling passion, in spite of obstacles, however alarming, or opposition, however strenuous and vigilant.  Mr. Dixon, a Roman Catholic priest, who had been sent under an order of transportation from Ireland, for his principles, accompanted Colonel Johnston on this service, and proved to be of some utility in bringing back the insurgents to a proper sense of their duty.  It cannot be too much to say, that the conduct of Mr. Dixon, before and after this business, was strictly exemplary.