A similar treaty with Prussia was concluded in 1785, not long before Dr. Franklin's departure from Europe.
Dr. Franklin did not suffer his political pursuits to engross his whole attention. Some of his performances made their appearance in Paris. The object of these was generally the promotion of industry and economy.
In the year 1784, when animal magnetism made great noise in the world, particularly at Paris, it was thought a matter of such importance, that the king appointed commissioners to examine into the foundation of this pretended science. Dr. Franklin was one of the number. After a fair and diligent examination, in the course of which Mesmer repeated a number of experiments, in the presence of the commissioners, some of which were tried upon themselves, they determined that it was a mere trick, intended to impose upon the ignorant and credulous—Mesmer was thus interrupted in his career to wealth and fame, and a most insolent attempt to impose upon the human understanding baffled.
The important ends of Dr. Franklin's mission being completed by the establishment of American independence, and the infirmities of age and disease coming upon him, he became desirous of returning to his native country. Upon application to congress to be recalled, Mr. Jefferson was appointed to succeed him in 1785. Some time in September of the same year Dr. Franklin arrived in Philadelphia. He was shortly after chosen member of the supreme executive council for the city; and soon after was elected president of the same.
When a convention was called to meet in Philadelphia, in 1787, for the purpose of giving more energy to the government of the union, by revising and amending the articles of confederation, Dr. Franklin was appointed a delegate from the State of Pennsylvania. He signed the constitution which they proposed for the union, and gave it the most unequivocal marks of his approbation.
A society for political enquiries, of which Dr. Franklin was president, was established about this period. The meetings were held at his house. Two or three essays read in this society were published. It did not long continue.
In the year 1787, two societies were established in Philadelphia, founded on the principles of the most liberal and refined humanity—The Philadelphia Society for alleviating the miseries of public prisons; and the Pennsylvania Society for promoting the abolition of slavery, the relief of free negroes unlawfully held in bondage, and the improvement of the condition of the African race. Of each of these Dr. Franklin was president. The labours of these bodies have been crowned with great success; and they continue to prosecute, with unwearied diligence, the laudable designs for which they were established.
Dr. Franklin's increasing infirmities prevented his regular attendance at the council-chamber; and, in 1788, he retired wholly from public life.