Special Correspondence. I learn from a very high authority, whose name I am not at liberty to mention, (speaking to me at a place which I am not allowed to indicate and in a language which I am forbidden to use)-that Austria-Hungary is about to take a diplomatic step of the highest importance. What this step is, I am forbidden to say. But the consequences of it-which unfortunately I am pledged not to disclose-will be such as to effect results which I am not free to enumerate.