Journal of Surgeon Alfred L. Castleman.

Saturday, 13th.–Moved this morning at 7, leaving Frederick behind us. At 8, crossed the Monocacy, (a beautiful stream,) at Buckeytown, Maryland. Here heavy firing in the direction of Frederick, but as the day advances, swinging around towards Harper’s Ferry, from which we infer that Burnside is driving the enemy. Burnside is one of our reliable men, and rarely fails in what he undertakes. The enemy has been promised that if he will come in force into Maryland, he will get fifty thousand recruits from the State. He has come. Will the promise be met? A few days will tell. We too bear more towards the Ferry; I hope to intercept the retreat. But we move more slowly. Why? God forbid that our General, so rapidly rising, should, as he approaches danger, fall into his old habit, and disappoint all of our new born hopes. We laid still a long time at Buckeytown, then moved slowly forward for two miles, having made only four miles march to-day. At 9 P. M., as I write this, we are called to move, and the journal of to-morrow must tell the events of the night.