Colonel.—I have the honor to hand you statement made by Illinois Crothers, of 1st Md. Rebel Cavalry, who came to this office to report.

I questioned him closely and on every point of importance, he seemed very ignorant. He was in this city several days without reporting, and to all appearances is as bitter a Rebel to-day as ever.

I took from him a document marked "A," which shows that it was generally known to the authorities in Virginia, that he was coming to Maryland, and unless they were sure he would return, he would not have been granted the liberty. You can also see that he came an unusual route, for a deserter, i. e., by the way of Richmond.

I have reliable information that all of the Rebel Spies, commissioned as such, are from the Signal Corps.

Harry Brogden, named in the document, was once in our hands, tried as a spy. Herewith I hand you Brogden's history.

I think that this document shows that he, (Crothers), came with the consent of the Rebel authorities, and with the intention to return.

I am, Colonel,
Very respy. your obdt. servt.,
H. B. Smith,
Lt. & Chief.

P.S.—Mrs. Keenan, of Winchester, should be arrested.

This is not the first transaction of the kind implicating Mr. Wm. Mitchell. (H. B. S.)

It required experience and skill to cull out the spies from among real deserters and refugees. Spies would swallow the oath of allegiance as easy as water. One of the best tests of probabilities, was to ascertain the route travelled in coming out from the Confederacy.