In doing this he should apply his observations chiefly to Jamaica, which contained more than half the slaves in the British West Indies; and if he should succeed in proving that no material detriment could arise to the population there, this would afford so strong a presumption with respect to the other islands, that the House could no longer hesitate whether they should, or should not, put a stop to this most horrid trade.

In the twenty years ending in 1788, the annual loss of slaves in Jamaica (that is, the excess of deaths above the births,) appeared to be one in the hundred.  In a preceding period the loss was greater; and, in a period before that greater still; there having been a continual gradation in the decrease through the whole time.  It might fairly be concluded, therefore, that (the average logs of the last period being one per cent.) the loss in the former part of it would be somewhat more, and in the latter part somewhat less, than one per cent; insomuch that it might be fairly questioned, whether, by this time, the births and deaths in Jamaica might not be stated as nearly equal.  It was to be added, that a peculiar calamity, which swept away fifteen thousand slaves, had occasioned a part of the mortality in the last-mentioned period.  The probable loss, therefore, now to be expected, was very inconsiderable indeed.

There was, however, one circumstance to be added, which the West India gentlemen, in stating this matter, had entirely overlooked; and which was so material, as clearly to reduce the probable diminution in the population of Jamaica down to nothing.  In all the calculations he had referred to of the comparative number of births and deaths, all the Negroes in the island were included.  The newly imported, who died in the seasoning, made apart; but these swelled, most materially, the number of the deaths.  Now, as these extraordinary deaths would cease, as soon as the importation ceased, a deduction of them ought to be made from his present calculation.

But the number of those, who thus died in the seasoning, would make up of itself nearly the whole of that one per cent. which had been stated.  He particularly pressed an attention to this circumstance; for the complaint of being likely to want hands in Jamaica, arose from the mistake of including the present unnatural deaths, caused by the seasoning, among the natural and perpetual muses of mortality.  These deaths, being erroneously taken into the calculations, gave the planters an idea that the numbers could not be kept up.  These deaths, which were caused merely by the Slave Trade, furnished the very ground, therefore, on which the continuance of that trade had been thought necessary.

The evidence as to this point was clear; for it would be found in that dreadful catalogue of deaths, arising from the seasoning and the passage, which the House had been condemned to look into, that one half died.  An annual mortality of two thousand slaves in Jamaica might be therefore charged to the importation; which, compared with the whole number on the island, hardly fell short of the whole one per cent. decrease.