...nited States, are entirely untrue. Since Sumter was attacked, it is well known no such idea has been considered in the Government's counsels. We hear, on authority, in which we confide, that Mr. W. B. Astor has tendered to the United States as an outright contribution to the cause of the Union, a donation of four millions of dollars, and ten millions more as a loan. His fortune enables him to do so, i...