They both had opportunities (the servant when she took away the tea, and the shopman when he came, after shutting up, to give the keys of the till to his master) of seeing the cash-box in Mr.Yatman's pocket, and of inferring naturally, from its position there, that he intended to take it into his bedroom with him at night.
Mr.Jay, on the other hand, had been told, during the afternoon's conversation on the subject of joint-stock banks, that his landlord had a deposit of two hundred pounds in one of them.

He also knew that Mr.
Yatman left him with the intention of drawing that money out; and he heard the inquiry for the cash-box afterward, when he was coming downstairs.

He must, therefore, have inferred that the money was in the house, and that the cash-box was the receptacle intended to contain it.

That he could have had any idea, however, of the place in which Mr.
Yatman intended to keep it for the night is impossible, seeing that he went out before the box was found, and did not return till his landlord was in bed.

Consequently, if he committed the robbery, he must have gone into the bedroom purely on speculation.
Speaking of the bedroom reminds me of the necessity of noticing the situation of it in the house, and the means that exist of gaining easy access to it at any hour of the night.
The room in question is the back room on the first floor.