There are two letters on file in my office obtained from Justice Donn which were written at Hartford, Conn., by Nettleton dated respectively May 26 and 30, 1861. In the former he says that he is out of money and that he hardly knows that to do to pay expenses; that he would be glad to have the money sent to him to aid in getting back to Washington; that he would enlist in the army but does not like to fight against the South. Sends his best respects to Ham Hughes and requests that he be advised to "blow out his light," an expression which axquires significane from being repeated in the second letter verbatim, and in close connection with his stating he will not return to Washington under five weeks as he intends going to Richmond and will stop about a week in Washington. Both these letters are addressed to a lady in Washington he calls "Deparest Laura. " One of my operatives learned that this "Darest Laura" was a notorious courtesan residing in Washington.

A package of several letters was found at the room of John W. Burson at the time of his arrest which was handed by Justice Donn to one of my operatives on the 18th instant, a brief of which letters in herewith submitted, the originals being on file in my office.

Your obedient servant,

E. J. ALLEN.

Brief of the letters found in the room of John W. Burson at the time of his arrest.

One letter dated Montgomery, Ala., April 17, 1861, addressed to John W. Burson and signed by B. F. Lum.

Numbers 1. - Lum acknowledges the receipt of Burson's letter of April 10. Says that he (Lum) is out of money and wishes Burson to send him some. Says things look fine since the fall of Sumter and that he excitment has died away. He tells Burson to expect lively times soon in Florida. Tells Burson he must hold on to his place and keep still about politics. (Burson was clerk in the Interior Department under Mr. Buchanan.) Lum urges as a reason why Burson should "hold on and keep still," that " are many days you will have Jeff. Davis to preside over your welfare: you may bet your life. " He says, "Old Abe has but very few days to remain in Washington, and I expect to be there to help drive him and many of his followers from every foot of sacred soild [which] belongs to the South: you may expect to see that before very long, and that will be glory enough for me. " You may say to Goodenough that he had a good many others will not be expected. " (This Goodenough appears to have been a Union man who was boarding at the same house with Burson, Emerson and Lum while they were all in Washington, and he (Goodenough) is referred to in one of Nettleton's letters as being a man standing very much in the way of their treasonable designs.) Lum says they are hourly expecting to hear of the ordinance of secession from Virginia, and that when that takes place there will be 100 guns fired in her honor for the example she sets to other border States. He says, "Tell Uncle Pres. that he is mistaken in supposing that any other element exists at the South besides that of secession. " He says all lines are abolished in favor of the single idea of Southern rights; that every man is ready at a moment's warning to shoulder his musket in defense of Southern rights and Southern honor; that he expects Maryland will be all right; that General Pillow is at Montgomery offering 5,000 troops to the Confederacy, and that he can raise 20,000 in Tennessee. He close by sending his respects to Nettleton.