The Sun. — 1863-05-15 (London, England)

RUSSIAN ATROCITIES.  A Warsaw letter in the Czas gives the following nformeion  " We have received some details respecting the engage. ment which took place on the 29th of April, at Suprasl, near Bialystok. At this affair several Russian officers and 80 soldiers joined the insurgents. The Russian report, as usual, claims the advantage; it pretends that the insurgents were driven back into the marshes, and estimates their loss at 30 killed. We shall wait for information from Polish sources. A band of assassins, organised and paid by the authorities of `Vilna, is, under the pretext of searching for arms, overrunning Livonia with sword and fire, pillaging, massacring, and burning everything on their way. A thousand of these wretches lately invaded the domain of Wyzki, the residence of Baron Moht, who had as guests at the Rio • ment his two brothers, Count Komar and Prince Mirski. Tnese three persons were shamefully ill-treated, and afterwards loaded with chains. The coachman, who was so bold as to defend his stables, had his skull split open by a blow from a hatchet, and was then quartered I A young Cossack in the service of the count was murdered. These horrible scenes were crowned by the burning of the chateau and all its dependencies. The three prisoners were thrown into a dungeon of the fortress of Dunabourg. Baron Mohl's peasants, far from joining in the pillage, aided in the escape of the baroness, whom they conducted disguised to the railway. Unfortunately, being recognised there by the soldiers, she bad to undergo ell kinds of ill treatment notwithstanding her being enciente. At Dunabourg, exhausted by suffering and fatigue, she had a miscarriage, attended with dreadful suffering. Another band broke into the residence of M. Urbain Benislaweki, who was also loaded with chains and taken to the fortress. The Abbe Krandra, cure of the district, was seized in 'he church and carried ff. The peasants saved M. Benislawski's three daughters. Fourteen other chateaux were pillaged and burned by the ruffians sent from Wilna. The peasants, disgusted at the sight of these infamies, have joined the insurgents in large numbers, and have opposed an energetic resistance to a band who attempted to pillage the chateau of Dubno. The National Government has reduced Colonel Seytried for not having arrived to the assistance of Jung in time."  RUMOURS OF MEDIATION,--A letter appears in the Rio tie Janeiro journals from General Webb, the American Minister, contradicting a report in that capital that the Federal Government had expressed a willingness to agree to the arbitration of the Emperor of Brazil in its quarrel st ith the South ; but adding that,' in the event of any arbitration, the choice of the cabinet of -Washington would no doubt fall on that Sovereign, who had so many claims to its respect and confidence.  A newly invented electro-metallic coating is about to be applied to the plates of the iron-cased steam frigates Gloire and Invincible. It appears that this new composition has been found to be very successful in the preservation of metals. The Minister of Marine has addressed a despatch to the several port-admirals instructing them to send a number of shipwrights to Paris to be instructed in the preparation of this new composition. Experiments likewise are about to be made to prevent the rolling of iron mod ships,