_May 6th._--Since I wrote the above, nearly a month ago, I have been out of the way of hearing anything on public affairs, till a day or two ago when I called on Clarendon, when he told me some things not without interest, partly about domestic and partly about foreign affairs. The latter of course related to the inexhaustible subject of the Emperor Napoleon's projects and machinations. His Majesty, it seems, has recently had a conversation with M. de Moustier, French Minister at Vienna, in the course of which he told him that it was an absolute necessity to France to carry her frontier to the Rhine. About the same time Cavour had signified (I forget whether it was to the same de Moustier or to some other person) that Sardinia must obtain possession of Venetia. These necessities, it can hardly be doubted, are expressed and resolved upon by a common accord. Austria has been already completely crippled by the late war; if threatened in Italy she will employ all her resources in defence of her Italian territory, and she will be quite unable, even if she were willing, to join in any measures of resistance to the attempts of France upon Germany. Prussia has had the egregious folly to renew her feud with Denmark upon the affair of Schleswig-Holstein, and is about to provoke a fresh war on that question. Denmark thus threatened appeals to France for aid, which France is too happy to afford, as she will thereby in all probability find a good pretext for interference, and for the furtherance of all her designs. There seems no doubt that a Treaty of some sort has been concluded between France and Denmark. In this difficult and menacing posture of affairs, England will sooner or later have to play a part of some sort, and it is disquieting enough to reflect upon our diplomacy being under the charge of John Russell and of Palmerston.