CINCINNATI, May 29, 1863.

General W. S. ROSECRANS:

Will you please forward by flag of truce the following dispatch to General Bragg? Please answer.

General BRAXTON BRAGG, Commanding Army of Tennessee:

Your letter in reference to John R. Lyle, convicted as a spy at Bowling Green, Ky., is received. The execution is deferred until further orders.

I take this opportunity to say that information has reached me that Captain McKee and another Federal officer are in close confinement in Richmond and sentenced to death in retaliation for the execution of McGraw and Corbin at Sandusky City. These two men were found within my lines in citizens' clothes recruiting for the enemies of my country. Every man so found will be tried and if convicted will suffer death.

Officers and soldiers taken in open warfare against my Government will be treated as prisoners of war. There can certainly be no complaint in your army of my treatment of such captives as I was the first general officer of our service who initiated a general system of parole by the release of the entire garrison captured on Roanoke Island, and I have ever since endeavored to treat prisoners of war according to the usages of modern warfare, but secret recruiting officers and spies as well as men from the country occupied by my forces who have become homesick and visit their families within our lines must expect to suffer death if caught and convicted by a court ordered by me, particularly if they are found in citizens' clothes. If they wish to spare their lives let them wear uniform, carry their arms and travel in a soldierly manner.

Every general in your army is at liberty to apply the same rule to my forces. I desire to make the following statement to the authorities at Richmond through you and ask you to forward it as the only means I have of communicating with them:

All officers of your army taken in open arms which I now hold and all that I may hereafter take will be placed at once in solitary confinement and there held till McKee and the other Federal officer now in Richmond are released in accordance with the cartel agreed upon and for every officer of my department taken in open arms who suffers death by direction of your authorities in the way of retaliation or otherwise ten of your officers, and in the absence of officers to fill up the number I will take the relatives and sympathizers of the officers from this department now in your army.

This is not made as a threat but is established as a rule to be inflexibly observed in this department.

Hoping your authorities may be influenced to adopt the policy of carrying on this war according to the modern code of civilized warfare,

I remain, respectfully, yours,

A. E. BURNSIDE,

Major-General.

A. E. BURNSIDE,

Major-General.

HEADQUARTERS SIXTEENTH ARMY CORPS, Memphis, Tenn., May 29, 1863.

Lieutenant Colonel JOHN A. RAWLINS, Assistant Adjutant-General.

COLONEL: I have the honor to report that Colonel C. B. Lagow, aide-de-camp, reported to me early this morning with 4,408 prisoners. Pursuant to your orders the guard was relieved about 12 m. to-day and Colonel Lagow was verbally directed by me to send his guard down at once.

Colonel Lagow does not appear to have paid any attention to this duty or to have taken any care of the officers and men under his charge, nor even to have known now many men constituted the guard. He informed me that they were about 1,000 and were to go below on the Emerald. Although I considered 1,000 a very heavy load for the Emerald still I thought it might be done. Three boats left here to-day, the Champion, the Courier and another with State authorities, sanitary