Count von Schlieffen, who proves to be as amiable a man as he is an able Chief of the Staff, tells me that news reached the German Headquarters this afternoon of a tremendous conflict between no fewer than five Cavalry Divisions, three on the Russian side and two on the Austrian, somewhere near Brod, on the Volhynian frontier—a conflict which resulted, as it could scarcely otherwise have done from the relative proportion of numbers, in the total defeat of the Austro-Hungarian horsemen. The latter, it seems, were covering the movements of the 3d Austrian Corps, which had been appointed to head an advance in the direction of Dubno; and when they had been overthrown in a _mêlée_ which, in its colossal magnitude, recalled the mounted conflicts of the Crusaders, the victorious Russians, rallying and reforming line, swept down upon a detached portion of the Austrian infantry, regardless of the smokeless volleys from the Mannlicher repeating rifle, and made awful havoc among the sturdy men from the Steiermark, taking one whole battalion prisoners, including, it is rumoured, the colonel of the regiment, the 27th, who is none other than Count Hartenau, better known as Prince Alexander of Battenberg, ex-Prince of Bulgaria—a wonderful piece of luck, indeed, for the Russians, if the rumour proves true. LATER. Later despatches confirm the rumour of Prince Alexander’s capture by the Russians, and add that, when the news became known at Dragomiroff’s headquarters—which are said to be at Dubno—there was almost as much jubilation as when the intelligence of Napoleon’s surrender flew like wildfire around the German lines at Sedan. The ex-Bulgarian Prince is to be sent to St. Petersburg, where rooms are being already prepared for him at the Katherinenhof, and meanwhile he has been allowed to retain his sword in order that his unforgiving and exultant cousin, the Czar, may have the satisfaction of receiving it from the humiliated captive’s own hands—a picture that will eclipse in interest all the romantic incidents which have already marked the Prince’s strangely chequered career. NIGHT ATTACK BY THE RUSSIANS. FIGHTING BY THE ELECTRIC LIGHT—ROUT OF GENERAL GOURKO—RETREAT UPON WARSAW. (_By Telegraph from our Special Correspondent, Mr. Charles Lowe._) ALEXANDROVO, _May 7_, 5 A.M. The German Army of the Vistula has just inflicted on the Russians another Plevna, and they are now in full retreat towards Warsaw. Such, in brief, is the result of the sanguinary night battle of which I have just been a witness. The Russians were the first to practise night attacks as a means of obviating the dreadful losses certain to result from magazine-rifle fire during the day, but they will long have cause to remember their first serious application of the nocturnal principle of modern warfare.