AUGUST 20TH.—Secretary Walker returned last night, having heard of the death of Col. Jones before reaching his destination. I doubt whether the Secretary would have thought a second time of what had been done in his absence, if some of his friends had not fixed his attention upon it. He shut himself up pretty closely, and none of us could see or hear whether he was angry. But calling me into his room in the afternoon to write a dispatch which he dictated, I saw, lying on his table, an envelope directed in his own hand to the President. Hints had been circulated by some that it was his purpose to resign. Could this communication be his resignation? It was placed so conspicuously before me where I sat that it was impossible not to see it. It was marked, too, “immediate.”