the headquarters of Major-General Banks, and in concert with Surg. W. S. King, U. S. Army, to examine into and report upon the sanitary characteristics of the ground now occupied by the troops and the positions suggested by General Banks in the neighborhood of Rockville and in Frederick County. Surgeon Keeney has performed this duty, and his report is herewith submitted..

The present position of the troops under General Banks is decidedly objectionable, for the reasons set forth in the report. Moreover, any severe rains would render the camps almost inapproachable as well as uninhabitable. I cannot therefore too strongly recommend their immediate removal..

The sanitary condition of this division is now excellent; and to preserve it in this condition a location with better drainage will be indispensable..

The choice seems to be between Rockville and Frederick. The hygienic reasons, in my opinion, are in favor of Frederick. I know this position to be eligible from personal observation. I had once before selected it for the general hospital of General Banks' division, and I consider the country about it as offering superior advantages for the location of camps and for the comfort of the troops. Rockville, from the nature of the soil, being less easily drained, and from being less protected against the prevailing winds in winter, will be likely to furnish a greater number of typhoid-fever cases and of diseases of the respiratory organs. Frederick promises greater immunity from these. Whether strategic reasons in favor of Rockville may decide that some greater risk of health should be incurred I am unable to say; if they do not, I would advise the removal of the division to Frederick, but either location will be far preferable to the present..

Very respectfully, your obedient servant,.

CHAS. S. TRIPLER,.

Surgeon and Medical Director, Army of Potomac..

[Inclosure.]

ARLINGTON, VA., November 18, 1861.

Surgeon TRIPLER, Medical Director, Army of Potomac:.

SIR: In obedience to your instructions to proceed to the headquarters of Major-General Banks, and in concert with Surgeon King, medical director, to examine into the medical topography of the camps of that division, I have the honor to state, we have made the examinations of those grounds as well as others, and submit to you the following observations:.

the face of the country in the neighborhood of Rockville is rolling, and sparsely covered with timber..

The soil is of clay, is moist and cold. The grounds are ample for a camp of 15,000 or 20,000 men, but would be cold and bleak from the northwesterly winds..

In a sanitary point of view, these grounds offer but few objections as regards fevers and other ailments arising from local causes..

The town of Rockville is distant 15 miles from Goergetown. The houses are few and of poor quality, affording limited accommodations for the sick and wounded of this division..

After the examination of these grounds I proceeded to the headquarters of General Banks, and in company with Surgeon King went over the campaign grounds of the division..

We found most of the regiments encamped on Muddy Branch, a small.