When the public attention was first called to this branch of the subject, it was alleged, and with considerable plausibility, that self-interest alone would be a sufficient security against abuses; for not only was the owner of the Slave ship interested in having the Slaves brought to the port of sale in the best possible condition; but the master, officers, and surgeons of the ships had all a similar interest, their profits being made to depend, in a considerable degree, on the average value of the cargo. To this argument from self-interest, it must be confessed, that more weight was justly due in this part of the case, than in any other; because the interest was nearer, and more direct, and was not counteracted by any interest of an opposite nature; yet even here it was proved but too decisively, that, as in other cases, nature was too hard for reason, the passions too powerful for interest. The habit of viewing, and treating these wretched beings as mere articles of merchandize, had so blinded the judgment, and hardened the heart, as to produce a course of treatment highly injurious to the interest of the owners and officers of Slave ships, and at the same time abounding in almost every circumstance that could aggravate the miseries of the Slaves. When the condition therefore and treatment of the Negroes on shipboard were first laid open, the indignation of the House of Commons was excited so strongly, that though the Session of Parliament had nearly closed, a Bill was immediately brought in and passed, with a view to mitigate their sufferings, during even the short period for which, it was then conceived, the existence of the Slave Trade could be tolerated. Human ingenuity had almost been exhausted in contriving expedients for crowding the greatest possible number of bodies into a given space; and when the smallpox, the flux, or any other epidemic, broke out among them, the scene was horrible beyond description. Even where there was no such peculiar aggravation, the sufferings of the poor wretches were such as exhausted all powers of description. Accordingly, the average mortality on board the Slave ships was very considerable. Often, during a voyage of a few weeks, so many perished, that if in any country the same rate of mortality should prevail, the whole population would be swept away in a single year. The survivors also were landed in such a diseased state, that four and a half per cent. of the whole number imported were estimated to die in the short interval between the arrival of the ship and the sale of the cargo, probably not more than a fortnight; and, after the Slaves had passed into the hands of the planters, the numbers which perished from the effects of the voyage were allowed to be very considerable[14].