16 JANUARY 1864, Page 3

M. Mazzini has absolutely denied all connection with the asserted

plot to destroy the Emperor, and all knowledge of three out of the four men connected with it. Greco he knew, and had some intercourse with, nine or ten months ago, and gives him a high -character as an Italian patriot, which Greco can scarcely deserve now, as he his, at least, clearly abused Manini's name, perhaps at the iustigation of the Parisian police. At present the whole .story of the plot has a very suspicious appearance, and M. Mazzini's letter, of which no one will doubt the strict accuracy, goes to increase our doubts of its genuineness.