afternoon of July 30. The train was stopped within a few yards of the prison, and the prisoners were marched under guard to the parlor of the prison. Each officer's name was called in turn and he was formally turned over to Mr. N. merion, the warden of the penitentiary, when he was searched, and everything valuable taken from him. The money, &c., was placed in a package labeled with the owner's named; a list of all articles registered. The package was then placed in the prison safe. This search was made in the presence of myself and staff, and also two of the directors of the penitentiary, and was done as delicately as possible. In most instances the officers delivered everything themselves, They were then conducted into the prison until after I had turned over the last prisoner, and was not aware that they were going to cut their hair and whiskers. Upon going into the prison I found that about two-thirds had gone through the process. I at once spoke to the directors on the subject. They replied that they could receive prisoners on no other conditions. That their cells were new, clean, and sweet; that most of the prisoners were filthy and covered with vermin, and that it was a mere sanitary measure and not a degradation. They were undoubtedly covered with vermin, and as most of them had undergone the treatment it was decided to treat them all alike. Their hair was not cropped, but was cut in the style usually worn by gentleman in this city, and was not more closely cut than my own. Their beards were cut close. No indignity was offered them. Many of them thought it a benefit, and quite a number requested afterward to renew the bath. Their money and valuables are now in the hands of the warden, just as they were received, except that small sums of money have been expended for them from time to time on their written orders. The prisoners are confined in a portion of the prison separated from the convicts, have their meals by themselves, and are allowed to be together during the day. At night they are locked in their cells.

No order was given by any military authority for the course of treatment on their first arrival, but the directors of the prison required the warden to enforce the usual sanitary regulations of the prison in their case. Subsequently, General Burnside directed that in future shaving, &c., be omitted. This was communicated at once to the prison authorities. I inclose a copy of Governor Tod's instructions to the warden, and also extracts from letters from two of the prisoners now confined, which will tend to show tat they have no cause for complaint of their treatment. They are not treated as convicts, but as nearly like prisoners of war as the circumstances of the case will admit. They are allowed as near the army rations as the facilities for cooking will admit, and are in every particular better cared for than any of our prisoners can be at Camp Chase.

Very respectfully, your obedient servant,

JNO S. MASON,

Brigadier-General of Volunteers.

[Inclosure Numbers 1.]

EXECUTIVE DEPARTMENT, Columbus, July 30, 1863.

NATHANIEL MERION, Esq., Warden of Ohio Penitentiary:

You have been advised of a formidable and destructive raid through our State of a band of desperate men under the lead of the notorious John H. Morgan, also of their capture by the military forces of the Federal Government, aided, however, materially by the militia forces.