Secrets of this kind, however, it must be acknowledged, can seldom be long kept; and the extraordinary profit can last very little longer than they are kept.

然而，必须承认，这种秘密很少能长期保守；超额利润的持续时间不会比它们被保留的时间长很多。

The establishment of any new manufacture, of any new branch of commerce, or of any new practice in agriculture, is always a speculation from which the projector promises himself extraordinary profits.

建立任何新的制造业，任何新的商业部门，或任何新的农业实践，总是一种投机，计划者承诺从中获得非凡的利润。

But as they are repeated upon every part of his stock, and as their whole amount bears, upon that account, a regular proportion to it, they are commonly considered as extraordinary profits of stock.

但是，由于它们在他的每一部分股票上都重复出现，并且由于它们的总量因此而与其成正比，因此它们通常被认为是股票的超常利润。