To render the introduction of penal labour into a colony an advantage, three things are necessary. 1st, that the convicts sent out should be for the most part instructed in some simple rural art or occupation, of use in the country into which they are to be transplanted. 2d, that they should in general be _beginners in crime_, and a small number of them only hardened in depravity. 3d, what is most important of all, that they should be preserved in a _due proportion_, never exceeding _a fourth or a fifth_ to the free and untainted settlers. Under these conditions, their introduction will always prove a blessing, and will be hailed as a boon. If they are neglected, they will prove a curse, and their arrival be regarded as a punishment. Various circumstances have contributed, of late years, to render the convict system a dreadful evil, instead of, as formerly, a signal benefit to the colonies. But that affords no ground for despair; on the contrary, it furnishes the most well-grounded reason for hope. We are suffering under the effects of an erroneous regimen, not any inherent malady in the patient. Change this treatment, and his health will soon return. It is well known that the greatest pains have of _late years_ been taken, in this country, to instruct prisoners in jail in some useful handicraft; and that, so far has this been carried, that our best-regulated jails are more in fact great houses of industry. The general penitentiary at Pentonville, in particular, where the convicts sentenced to transportation are trained, previous to their removal to the penal settlements, is a perfect model of arrangement and attention in this important respect. But it is equally well known that it is only of _late_ years that this signal reform has come into operation; and we have the satisfaction of knowing that already its salutary effects have been evinced, in the most signal manner, with the convicts sent abroad. Previous to the year 1840, scarcely anything was done on any considerable scale, either to teach ordinary prisoners trades in jail, to separate them from each other, or to prepare them, in the public penitentiaries, for the duties in which they were to be engaged, when they arrived at their distant destination. The county jails, now resounding with the clang of ceaseless occupation, pursued by prisoners in their separate cells, then only re-echoed the din of riot and revelling in the day-rooms where the idle prisoners were huddled together, and beguiled the weary hours of their captivity by stories of perpetrated crime, or plans for its renewal the moment they got out of confinement. But the ideas of men are all formed on the experience of facts, or the thoughts driven into them, for a considerable time back. The present universal horror at transportation is founded on the experience of the prisoners with which, for a quarter of a century, New South Wales had been flooded, from the idle day-rooms or profligate hulks of Great Britain.