Plain-dealing is best.

If you have any particular mark, Mr.Baboon, whereby one may know when you fib and when you speak truth, you had best tell it me, that one may proceed accordingly.

But since at present I know of none such, it is better that you should trust me than that I should trust you.
LEWIS BABOON .-- I know of no particular mark of veracity amongst us tradesmen but interest; and it is manifestly mine not to deceive you at this time.

You may safely trust me, I can assure you.
JOHN BULL .-- The trust I give is, in short, this: I must have something in hand before I make the bargain, and the rest before it is concluded.
LEWIS BABOON .-- To show you I deal fairly, name your something.
JOHN BULL .-- I need not tell thee, old boy; thou canst guess.
LEWIS BABOON .-- Ecclesdown Castle,* I'll warrant you, because it has been formerly in your family.

Say no more; you shall have it.
* Dunkirk.
JOHN BULL .-- I shall have it to my own self?
LEWIS BABOON .-- To thine own self.
JOHN BULL .-- Every wall, gate, room, and inch of Ecclesdown Castle, you say?
LEWIS BABOON .-- Just so.
JOHN BULL .-- Every single stone of Ecclesdown Castle, to my own self, speedily?
LEWIS BABOON .-- When you please; what needs more words?
JOHN BULL .-- But tell me, old boy, hast thou laid aside all thy equivocals and mentals in this case?
LEWIS BABOON .-- There's nothing like matter of fact; seeing is believing.
JOHN BULL .-- Now thou talkest to the purpose; let us shake hands, old boy.