JULY 17TH.—The news is not so good to-day. Gen. Garnet’s small command has been defeated by the superior numbers of Gen. McClellan. But the general himself was killed, fighting in the rear of his retreating men. His example will not be without its effect. Our generals will resolve never to survive a defeat. This will embolden the enemy to attack us at Manassas, where their suddenly acquired confidence will be snuffed out, or I am mistaken.