The London _Spectator_ thinks it highly probable that the malcontents are masters of all the provinces south of the Yellow River, and have seized upon the great entrepot of Canton. This, it adds, would be a revolution; for Pekin, which derives its supplies of provisions by the great canal from those southern provinces, would be starved into submission; and the principal seat of foreign commerce would fall into the hands of a party more bigotedly hostile to intercourse with foreigners than even the Celestial Government. Nor is such a revolution either impossible or improbable. Our knowledge of Chinese history is dim and obscure; yet enough appears to show that the Mantchoo authority has never been so firmly established to the south as to the north of the Yellow River--that the purely Chinese element of society has always preponderated in the southern provinces. In _Siam_, too, changes of policy appear to be impending. The king who refused to treat with Sir James Brooke is dead; and a contested succession has been temporarily avoided by the simultaneous nomination of a king and a vice-king. The new king has always been remarkable for his disposition to cultivate the acquaintance and friendship of foreigners, and he is said to understand and even to write English. The institutions of the Chinese and Hindu-Chinese nations are thus shaken and sapped at the very time when the traders of Europe and America are making more vigorous and continuous efforts than at any former period to obtain a footing in them. Twenty-three British seamen belonging to the ship Larpent, were wrecked over a year ago upon the coast of the Chinese island of Formosa. They were immediately set upon by the savage inhabitants, and all but three butchered in cold blood. These three were taken into servitude, and after about eight months' captivity made their escape in a boat to an American brig which happened to be passing. Editor's Table.