The PENNSYLVANIA Legislature is now in session. The message of Gov. JOHNSTON states the amount of the Public Debt at $40,775,485. The Governor recommends that all the elections be hereafter held in October. The project of erecting an Agricultural Department is commended to favorable consideration. An appropriate arrangement of the geological specimens belonging to the State is also urged. The large body of original papers in the State Department connected with the Colonial and Revolutionary History of the State are in an exposed and perishing condition, and are recommended for better preservation. In the early spring the buildings of the Insane Asylum will be ready for the reception of patients. The school system, although still imperfect, is rapidly improving in its general condition, and promises the beneficial results it was designed to accomplish. The full repair of the canals and railroads of the State is urged as an important measure. A system of banking, based upon State stocks, under proper restrictions, is recommended to the attention of the Legislature. It is thought that the present banking facilities are unequal to the wants of the business community. On national questions, Gov. JOHNSTON takes ground in favor of a revision and alteration of the revenue laws, so as to give adequate and permanent protection to the industry of the country, the reduction of postage, and the construction of railway communications to the Pacific--and in regard to the question of slavery and the Fugitive Law, counsels obedience to the laws and respect to national legislation; but excepts to that part of the law which authorizes the creation of a new and irresponsible tribunal under the name of Commissioners. MEXICO. Intelligence from the city of Mexico is to the 30th of November. Congress was still engaged in discussing various propositions concerning the public debt, and a bill had passed both houses for regulating the interior debt, the original amount of which was about seventy-five millions of dollars, the new law, however, reduces it about one-third. It is believed that the new steps taken upon this subject will prove highly advantageous to the country. The magnetic telegraph is in operation in the city of Mexico merely as an experiment, and gives general satisfaction. Efforts are being made to form a company for placing it from Mexico to Vera Cruz.