"Some of the questions on which Mr. O'Conor's opinion is desired in the first instance are the following:
"First.—If to the Bill of Discovery a plea, or an answer in the nature of a plea, should be made denying the right of action of the United States in the suit in the district court, and, consequently, its claim to a discovery on the ground that the quasi judicial determination of the assessor as to the amount of the tax, and the satisfaction of the judgment rendered by him are conclusive against the United States, and if the Circuit Court should overrule that point and grant the discovery, would that decision of the Circuit Court be a final judgment on which an appeal would lie to the Supreme Court?
"Second.—Would that appeal probably be effectual to obtain the rulings of the Supreme Court on the main question of the controversy?
"First.—If to the Bill of Discovery a plea, or an answer the defendant's income was in excess of the amount found by the assessor to be his income, calls on the defendant to state on oath every item of income during ten years, and every item of deductions therefrom and many items of receipts which are not income. There is no proposition between the foundation and the superstructure.
"What are the rules applicable to such a case?
"The interrogatories are not even limited to taxable income, but would involve accretions of value which are not taxable.
"Can the objection (a) that there is not any proper foundation for any interrogations? (b) that an interrogatory is too broad? (c) that an interrogatory relates to a matter in which the plaintiff has no interest or concern, as, for instance, to a subject not within the tax laws—can such objections be taken by way of special plea if we prefer that mode?
"The opinion or advice on the first and second questions is more emergent—the others can be dealt with later."