Mr. Seward to Mr. Prevost.

Sir: I have to acknowledge the receipt, on the 3d instant, of your despatch of the 10th ultimo, with its enclosures, marked A, B, and C.

The course you have pursued respecting the non-payment of the instalment due on the 17th of February last by the republic of Ecuador, is fully approved.

You will, on receipt of this despatch, address a note to the minister for foreign affairs of that government, and make a peremptory demand for the payment of that instalment, now over due.

Meanwhile, I have to inform you that the correspondence which has hitherto taken place between yourself and the department will be immediately submitted to Congress for their consideration.

I am, sir, your obedient servant,

WILLIAM H. SEWARD.

Louis V. Prevost, Esq., &c., &c., &c.