Letter from Lord Ponsonby to Henry John Temple, third Viscount Palmerston, concerning Colonel Chesney, the prospect of the Sultan going to war with Mehemet Ali, using the Turkish envoy to London to encourage British influence on the Sultan, Monsieur Blaque's secret mission to France and England, Russian manoeuvres in the Black Sea, the evacuation of Silestria, the case for British squadron being sent to the Dardanelles, recommending a knighthood for his agent Dr McGuffog, the necessity of having dragomen attached to the embassy, and an outbreak of the plague at Constantinople