Mr. Seward to Mr. Welles.

Sir: It is thought expedient that instructions be given to the blockading and naval officers that in case of capture of merchant vessels suspected or proved to be vessels of the insurgents, or contraband, the public mails of any friendly or neutral power, duly certified or authenticated as such, shall not be searched or opened, but be put as speedily as may be convenient on the way to their designated destinations. This instruction, however, will not be deemed to protect simulated mails verified by forged certificates or counterfeited seals.

I have the honor to be, sir, your obedient servant,

WILLIAM H. SEWARD.

Hon. Gideon Welles, Secretary of the Navy.