(M.) _Steamboat Knickerbocker, May 13th._—If my letter smells of Yellow B, it has a right to, as my paper is the cover of the sugar-box. Since I last wrote, we have been jerking about from boat to boat, fitting up one, and starting her off, then doing the same by another. We came on board this boat Saturday night. She had then about two hundred wounded men on board, taken from the Williamsburg fight, and bound for Fort Monroe, two of the ladies and assistants to look after the sick during the few hours' run, and others to get things on hand, and fit up the wards. We had fifty-six Commission beds made on the upper ward floor that night, and were ready to go on shore at Fort Monroe after the three and a half hours from Yorktown. Dr. C. came on board and had all the men carefully removed to the Hygeia Hospital, and we improved the opportunity to get some roses from the garden for our wounded men left on the _Small_, and to see Mr. Lincoln driving past to take possession of Norfolk. We lay at the fort all night, and were blown awake the next morning by the explosion of the _Merrimack_, when I found to my amazement that along-side of us lay the _Daniel Webster_, No. 2, Government hospital, with four or five of our Commission company on board, whom we had left at Yorktown. She ran, in passing, along-side our supply ships, (all our boats of the Sanitary Commission are known by their flags,) just after we came away, and begged for help. Mr. A. tossed on board everything necessary, including two ladies, two surgeons, and blankets, and started them off after us to the Fortress, with two hundred badly wounded men. They had been wholly uncared for till our people got on board. They did all they could for them in so short a time, washed them, gave them good suppers and breakfasts, and Drs. W. and W. dressed the worst wounds, watching them all night as tenderly as women could. This boat was all the next day unloading her sick; they were miserably wounded, and had to be lifted with great care. We on the _Knickerbocker_ started up the river again, and anchored off Yorktown.... We wanted a stove for our hospital kitchen on board, which has to be kept distinct from the kitchen of the ship's crew; so we went ashore with —— to seize upon anything we could find; poked about in all the rebel barracks, asked all the soldiers we met about it, and finally came upon the sutler's hut,—sutler of the _Enfans Perdus_, who was cooking something nice for the officers' mess over a stove with _four_ places for pots! This was too much to stand, so under a written authority given to "Dr. Olmsted" by the Quartermaster of this department, we proceeded to rake out the sutler's fire and lift his pots off;—and he offered us his cart and mule to drag the stove to the boat, and would take no pay! So, through the wretched town, filled with the _débris_ of huts and camp furniture, old blankets, dirty cast-off clothing, smashed gun-carriages, exploded guns, vermin and filth