The Tribune’s Washington dispatch says a German printer boy who has been a year getting from New Orleans via Richmond, where he was imprisoned three months, has arrived here.

He estimates the number of fighting men at Richmond at 70,000, and confirms the report that four divisions under Longstreet, Ewell, Hill and Jackson are stationed along the railroad from Staunton to Gordonsville, and at Louisa Court House, under Stonewall Jackson, numbering in all. in his opinion, 50,000 men: but it is improbable that these divisions average more than 12,000 after the severe fighting on the Chickahominy. Thirty thousand is probably nearer the number. Their pickets extend to New Market, and their course appears to be up the Shenandoah Valley.

A letter from Norfolk states that there have been several cases of yellow fever there.

The Yankees, it would seem, go into battles as they would go into water, with life-preservers on. We have had exhibited to us one of these steel breast-plates found on the persons of prisoners, and taken from the dead bodies of the slain. It is in the shape of the two breasts of a vest, and is made up in its folds, being sewed between the cloth and the lining. Except by its stiffness, and weight, which is about three pounds, it has all the appearance of an ordinary waistcoat. These steel waistcoats are manufactured in New York, and are quite in vogue in the Yankee army, especially among the officers. They are purchased at twenty five dollars apiece, and are warranted to repel a musket or pistol ball at ordinary range.