“ As the collector has no general authority to sell lands, at his discretion, for the non-payment of the direct tax, but a special power to sell in the particular cases described in the act, those cases must exist, or his power does not arise. It is a naked power, not coupled with an interest; and in all such cases, the law requires that every pre-requisite to the exercise of that power must precede its exercise; that the agent must pursue the power, or his act will not be sustained by it. ”

“ In the act of congress, there is no declaration that these conveyances shall be deemed prim a facie evidence of the validity of the sale. Is the nature of the transaction such, that a court ought to presume in its favor anything which does not appear, or ought to relieve the party claiming under it from the burden of proving its correctness? ”

“ It is easy, for example, to show that the collector has posted up the necessary notifications in four public places in his collection district, as is required by the 9th section, but very difficult to show that he has not. He may readily prove that he has made a personal demand on the person liable for the tax, but the negative, in many cases, would not admit of proof. ”