Porto Plata, September 8.- The revolutiou against President Baez has assumed alarming proportions, and there ig every prospect of its speedy success. The towns of Monte Christo and Guayabin are in tbe possession of the revolutionists, who are also in close proximity to Porto Plato. Great confusión exista here, and numorous families are preparing for fligbt. Martial law has been proolaimed, and an attack from the revolutionists is momentariiy expected. The sudden chango in favor of therevolutionists was cansed by Gen. Qarcia, of the Baez party, espouiing tbe vevolutionary cause with 600 men. The war cry of the revolutionists is " Down with the Samana Convention and Baez." There is erery reason to believe that the rising wiU uot injure business, as the revolutionary party promises to abstain trom prosecuting any one.