More of the awful toll of 36,000 taken from the Union army during the terrible Wilderness campaign. The Sanitary Commission is visiting the field hospital established near the Rappahannock River, a mile or so from the heights, where lay at the same time the wounded from these terrific conflicts. Although the work of this Commission was only supplementary after 1862, they continued to supply many delicacies, and luxuries such as crutches, which did not form part of the regular medical corps paraphernalia. The effect of their work can be seen here, and also the appearance of men after the shock of gunshot wounds. All injuries during the war practically fell under three headings: incised and punctured wounds, comprising saber cuts, bayonet stabs, and sword thrusts; miscellaneous, from falls, blows from blunt weapons, and various accidents; lastly, and chiefly, gunshot wounds. The war came prior to the demonstration of the fact that the causes of disease and suppurative conditions are living organisms of microscopic size. Septicemia, erysipelas, lockjaw, and gangrene were variously attributed to dampness and a multitude of other conditions. [Illustration: A CHANGE OF BASE--THE CAVALRY SCREEN COPYRIGHT 1911 PATRIOT PUB. CO.] This photograph of May 30, 1864, shows the Federal cavalry in actual operation of a most important function--the "screening" of the army's movements. The troopers are guarding the evacuation of Port Royal on the Rappahannock, May 30, 1864. After the reverse to the Union arms at Spottsylvania, Grant ordered the change of base from the Rappahannock to McClellan's former starting-point, White House on the Pamunkey. The control of the waterways, combined with Sheridan's efficient use of the cavalry, made this an easy matter. Torbert's division encountered Gordon's brigade of Confederate cavalry at Hanovertown and drove it in the direction of Hanover Court House. Gregg's division moved up to this line; Russell's division of infantry encamped near the river-crossing in support, and behind the mask thus formed the Army of the Potomac crossed the Pamunkey on May 28th unimpeded. Gregg was then ordered to reconnoiter towards Mechanicsville, and after a severe fight at Hawes' shop he succeeded (with the assistance of Custer's brigade) in driving Hampton's and Fitzhugh Lee's cavalry divisions and Butler's brigade from the field. Although the battle took place immediately in front of the Federal infantry, General Meade declined to put the latter into action, and the battle was won by the cavalry alone. It was not to be the last time. COLD HARBOR Cold Harbor is, I think, the only battle I ever fought that I would not fight over again under the circumstances. I have always regretted that the last assault at Cold Harbor was ever made.--_General U. S. Grant in his "Memoirs."_